ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (17,362)
  • Springer  (17,362)
  • 2020-2024
  • 1995-1999  (17,362)
  • 1999  (17,362)
  • Physics  (17,362)
Collection
  • Articles  (17,362)
Source
Keywords
Publisher
Years
  • 2020-2024
  • 1995-1999  (17,362)
Year
Journal
Topic
  • 1
    Electronic Resource
    Electronic Resource
    Orientation and crystallisation mechanisms during fast drawing of poly(ethylene terephthalate) (1999)
    Springer
    Polymer bulletin 42 (1999), S. 357-363 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Synchrotron radiation has been used to record the diffraction patterns from Poly(ethylene terephthalate) for a range of draw rates (0.1 to 10sec−1) and temperatures (90 to 120°C). The patterns were analysed to derive the development of the 〈P 2(cosθ)〉 order parameter and the rates of crystallisation. The effects of temperature and draw rate can be unified with a WLF time-temperature shift factor. Comparison with estimates of chain relaxation processes show that, when the draw rate is faster than the chain retraction process, the onset of crystallisation is delayed until the end of drawing. Crystallisation is very sensitive to both temperature and orientation and has an approximate 4th power dependence on 〈P2(cosθ)〉.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050475
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Poly(2,6-dimethyl-1,4-phenylene oxide)/polystyrene blends: thermodynamic interactions from glass transition data (1999)
    Springer
    Polymer bulletin 42 (1999), S. 441-448 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The glass transition temperatures of several blends of poly(2,6-dimethyl-1,4-phenylene oxide) and polystyrene have been measured by DSC, and the T g -composition data have been described on the basis of a thermodynamic treatment. A negative enthalpy of mixing and a positive entropy of mixing have been found, in agreement with the well known miscibility of the blend. The presence of a singolarity point in the T g -composition plot has been evidenced and considered at the light of a theoretical treatment recently proposed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050487
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and properties of new AB-type semi-crystalline poly(ether imide)s (1999)
    Springer
    Polymer bulletin 43 (1999), S. 157-163 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Two AB-type poly(ether imide)s were prepared by one-pot polyimidization in N-methyl-2-pyrrolidone(NMP)/pyridine or N,N-dimethylacetamide(DMAc)/Et3N solution in the presence of triphenylphosphite(TPP) activator. The polymers were obtained with inherent viscosities of 1.16(5a) and 0.54(5b) dL/g and were highly thermostable up to at least 552°C with 5% weight loss. The polymers showed chemical resistance against chloroform even at higher temperature but could readily be dissolved in m-cresol and concentrated sulfuric acid. Wide-angle X-ray diffractograms revealed that the polymers were semi-crystalline.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050547
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Synthesis of novel organocobalt poly(arylene-vinylene)s containing (cyclobutadiene)cobalt moieties in the main chain (1999)
    Springer
    Polymer bulletin 43 (1999), S. 165-170 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Organocobalt poly(arylene-vinylene)s composed of 1,2- or 1,3- linkage at their cyclobutadiene moieties (3 and 4, respectively) were prepared by the Heck reaction of p-divinylbenzene with (cyclobutadiene)cobalt-containing monomers having two aryl bromide moieties (1 and 2, respectively). The number average molecular weights (M n) of the obtained organocobalt poly(arylene-vinylene)s (3 and 4) were 4,100 and 4,000, respectively (GPC, on the basis of polystyrene). UV-vis spectra of 3 and 4 exhibited main π-π* absorption peaks at 362 and 397 nm, respectively, which were ca. 60 nm bathochromically shifted from those of the corresponding monomeric units. Both polymers were found to show thermotropic liquid crystallinity in the range of room temperature to ca. 80 °C by employing differential scanning calorimetry (DSC) and the optical measurement using crossed polarizers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050548
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Vinyltrimethoxysilane-co-2-vinylpyridine copolymer Synthesis and monomer reactivity ratios (1999)
    Springer
    Polymer bulletin 43 (1999), S. 171-175 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Copolymers containing vinyltrimethoxysilane (VTMOS) and 2-vinylpyridine (2VPy) at different compositions were synthesized and characterized. The monomer reactivity ratios r1 and r2 were estimated by using the classical Fineman-Ross and Kelen Tüdos linear fitting procedures. Moreover, these parameters were also estimated using a nonlinear computational fitting known as Reactivity Ratios Error in Variable Method (RREVM). Attempts to obtain the corresponding copolymer with vinyltrimethylsilane (VTMS) were performed but only hompolymerization 2VPy is observed due to the non-reactivity of VTMS under this conditions. The results were analysed in terms of the relative comonomeric structures and compared with similar related systems. The reactivities are interpreted in terms of the resonance and stabilization effects together with the chemical structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050549
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Synthesis of alkoxycarbene-containing polymers and their application as polymeric catalysts for phenylacetylene polymerization (1999)
    Springer
    Polymer bulletin 43 (1999), S. 177-182 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Polymers having Fischer-type alkoxycarbenes in the side chain were synthesized by the reaction of pendant hydroxy groups with pentacarbonyltungsten acetoxyphenylcarbene [(CO)5W=C(Ph)O2CCH3, 2]. Namely, copolymers of methyl methacrylate with 4-hydroxybutyl methacrylate [poly(MMA-co-HBMA), 3b] were prepared and subjected to the reaction with 2 derived from tetramethylammonium salt of pentacarbonyltungsten hydroxyphenylcarbene [(CO)5W=C(Ph)ON(CH3)4, 1] with acetyl chloride. Soluble copolymers (4b) with pendant metal-carbene segments were obtained, and 1H NMR and UV spectroscopic analyses indicated that the metal-carbene moiety was introduced onto 20–70% of hydroxy groups of the copolymers. In contrast, the introduction of carbene moiety into a copolymer of MMA with 2-hydroxyethyl methacrylate [poly(MMA-co-HEMA), 3a] was unsuccessful because no reaction with 2 took place. The formed polymer (4b) served as a polymeric catalyst for the polymerization of phenylacetylene under the photo-irradiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050550
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Synthesis of poly(N,N-dimethylcarbamoylmethylene) as a polymer homolog of N,N-dimethylacetamide (1999)
    Springer
    Polymer bulletin 43 (1999), S. 183-190 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary A novel polymer homolog of N,N-dimethylacetamide (DMAc) having amide groups on all main chain carbons, poly(N,N-dimethylcarbamoylmethylene) 1, was prepared by heating poly(di-t-butyl fumarate) 2 at 180 °C for 2 hours followed by treatment with hexamethylphosphoramide at 180 °C for 5 hours. The structure of the obtained polymer 1 was confirmed by 1H-, 13C-NMR and IR spectroscopy. The polymer 1 actually showed the properties based on its repeating structures. 1 had the amphiphilicity and was soluble both in protic and aprotic solvents. Furthermore, 1 showed the miscibility with commodity polymers such as poly(N-vinylpyrrolidone), poly(vinyl alcohol) and poly(vinyl chloride). In comparison with another polymer homolog of DMAc, poly(2-methyl-2-oxazoline), the polymer 1 exhibited better miscibility with poly(N-vinylpyrrolidone).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050551
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Polyamides containing α-aminoacids and hydrophilic oxyethylene groups along the chain (1999)
    Springer
    Polymer bulletin 43 (1999), S. 191-198 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Biocompatible and potentially biodegradable polyamides (PAs) containing in the chain both peptide bonds and hydrophilic triethyleneoxide segments have been prepared by interfacial polycondensation of sebacoyl dichloride with amide-diamines derived from the 4,7,10-trioxa-1,13-tridecanediamine and α-aminoacids such as glycine, L-valine and L-phenylalanine. These PAs exhibit moderate inherent viscosity values and show limited solubilities in CHCl3, DMF and DMSO. 1H-NMR and FTIR spectroscopy analysis confirmed the expected structures. DSC and X-rays diffraction spectra indicated crystallinity degrees from 19 to 31%. The melting temperatures range between 135–238 °C. Liquid water absorption measurements indicate a high equilibrium weight-uptake when a glycine residue is present in the amide-diamine moiety. In vitro tests carried out using cultures of human fibroblasts showed the biocompatibility of the prepared PAs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050552
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    New catalyst systems for polymerization of substituted acetylenes: W(NO)2(O2CR)2-MCl4(M=Ti, Sn) (1999)
    Springer
    Polymer bulletin 43 (1999), S. 199-206 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary W(NO)2(O2CR)2 - Lewis acid (LA) catalysts (LA=TiCl4, SnCl4; R=-CH(C2H5)(CH2)3CH3) induce substituted acetylenes (phenylacetylene, propargyl ether, 1,6-heptadiyne, diphenylacetylene) to polymerize or oligomerize. Their catalytic ability strongly depends on the Lewis acid and solvent. The polymerization reactions of phenylacetylene always accompany the cycolotrimerization reactions. In the system with TiCl4 in CH2Cl2 the yield of polymer equals to 56% at 80% conversion of a monomer. However, in the system with SnCl4 in benzene, 42% cyclotrimers arise at 57% conversion of phenylacetylene. The mechanism of these reactions as well as the structure of the obtained polymers were determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050553
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Catalyst effect on the transesterification reactions between polycarbonate and polycaprolactone-B-polydimethylsiloxane triblock copolymers (1999)
    Springer
    Polymer bulletin 43 (1999), S. 207-214 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Transesterification reactions between bisphenol-A polycarbonate and polydimethylsiloxane-polycaprolactone block copolymers were studied in melt at 270°C. Influence of the composition of reaction mixture and the catalyst type on the formation and properties of the products obtained were investigated by spectroscopic, chromatographic and thermal methods. Both of the catalysts used, zinc acetate and lanthanum acetylacetonate are very efficient transesterification catalysts for the system studied. GPC and DSC results clearly show the formation of novel polymers displaying combined properties of the polycarbonate and the silicone-ester copolymer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050554
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Termination mechanism of polymethyl methacrylate and polystyrene studied by ultrasonic degradation technique (1999)
    Springer
    Polymer bulletin 43 (1999), S. 215-222 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary A new method for determining the dominant termination mechanism in radical polymerization based on ultrasonic scission of long chains is used to study the termination of polystyrene and polymethyl methacrylate. The method is extended to obtain the disproportionation/combination ratio. Long dead polymer chains in solution were broken by ultrasound. The chain radicals thus formed were then allowed to terminate in the presence and absence of a chain terminating agent (radical trap). The resulting molecular weights are compared to find the dominant termination mechanism. It is found that the dominant mechanism in polystyrene is combination and that in polymethyl methacrylate is disproportionation. These results are in accordance with those quoted in the literature and obtained by other methods.The effectiveness of the radical trap used (2-chloroethyl benzene) was tested by NMR and it was found that when the trapping agent is present it terminates 100% of the polymethyl methacrylate chains. The time evolution of the degree of polymerization was compared to simulations based on Schmid's model. The disproportionation/combination ratios were found for polymethyl methacrylate as 2 and for polystyrene as 1/7 respectively through simulation studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050555
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Poly(β-malic acid) derivatives with non-charged hydrophilic lateral groups: synthesis and characterization (1999)
    Springer
    Polymer bulletin 43 (1999), S. 297-304 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Poly((3-hydroxypropyl β malate) has been synthesized starting from aspartic acid and benzyloxy-1-propanol as precursors. This new polymer was characterized by 1H and 13C NMR, size exclusion chromatography and differential scanning calorimetry. Homopolymer is soluble in water. Two kinds of amphiphilic copolymers were also prepared and characterized. Such polymers have been synthesized with a view to preparing non-charged degradable associating networks or drug carriers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050614
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Synthesis and properties of poly(phenylacetylene)s with pendant imino groups (1999)
    Springer
    Polymer bulletin 43 (1999), S. 305-310 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Polymerization of phenylacetylenes containing imino groups with a variety of transition metal catalysts was investigated. The monomers employed were N-(4-ethynylbenzylidene)aniline (1), N-(3-ethynylbenzylidene)aniline (2), N-(4-ethynylbenzylidene)-2,6-diisopropylaniline (3), N-(4-ethynylbenzylidene)-4-hexylaniline (4), N-(4-ethynylbenzylidene)butylamine (5), and N-(4-ethynylbenzylidene)octylamine (6). All of the monomers smoothly polymerized with [(nbd)RhCl]2-Et3N to give polymers in excellent yields, whereas no polymerization took place with W, Mo, and Fe catalysts. The produced polymers were orange to red solids and soluble in common organic solvents except for poly(1). UV-vis spectra of the polymers indicated that the main chains possess a similar degree of conjugation to that of poly(phenylacetylene). However, the stability of polymer backbone toward oxidative cleavage in solution remarkably improved, which is contributed by the electron-withdrawing character of imino groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050615
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Controlled polymerization of methylmethacrylate and ethylacrylate using tris(4,4'-dimethyl-2,2'-bipyridine) copper(II) hexafluorophosphate complexes and aluminium isopropoxide (1999)
    Springer
    Polymer bulletin 43 (1999), S. 319-326 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The radical polymerization of methylmethacrylate and ethylacrylate was carried out in the presence of tris(4,4'-dimethyl-2,2'-bipyridine) copper(II) hexafluorophosphate complexes and aluminium isopropoxide. The molecular weight of the synthesized polyethylacrylates increased proportionally with conversion, whereas the polymerization of methylmethacrylate revealed a nonlinear behavior. The polydispersities of the molecular weight distributions observed were between 1.09 and 1.34. Poly(styrene-block-polymethylmethacrylate) was synthesized by sequential monomer addition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050617
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Synthesis and the properties of novel cycloaliphatic-aromatic polyamides having pendent N,N'-diphenyl imido groups (1999)
    Springer
    Polymer bulletin 43 (1999), S. 311-318 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: ABSTRACT : We have investigated a novel monomer having two pendent phenyl imido groups for preparing new cycloaliphatic-aromatic polyamides. Novel polyamides were synthesized by direct polycondensation reaction of N,N'-diphenyl-2,3,5,6-diimido cyclohexane-1,4-dicarboxylic acid(PICA) and various aromatic diamines such as p-phenylene diamine, 4,4'-oxydianiline and 4,4'-methylene dianiline. A direct polycondensation was carried out by a Yamazaki method which is typical of using triphenyl phosphite, lithium chloride, and pyridine. Inherent viscosity of these resulting polyamides are ranged 0.20 ∼ 0.45 dl/g. A transparent flexible and tough film was casted. The glass transition temperature of the polyamide from the PICA and 4,4'-oxydianiline is 147 °C. The decomposition temperature of these polyamides are ranged from 350 ∼ 360 °C and the ash contents of them orders MDA 〉 p-PDA 〉 ODA according to kinds of the using diamines. And the solubilities of these polyamides are good in aprotic solvents such as DMAc, NMP, DMF.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050616
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Chain transfer reaction in metallocene catalyzed ethylene copolymerization with allyltrimethylsilane (1999)
    Springer
    Polymer bulletin 43 (1999), S. 333-340 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary In order to investigate the polymerization behavior of allytrimethylsilane as a comonomer, ethylene was copolymerized with allyltrimethylsilane at 80°C in toluene using methylaluminoxane (MAO) activated metallocene catalysts. The catalytic activity of the polymerization strongly depended on both the type of the catalysts and the concentration of allyltrimethylsilane. End group analysis of the copolymers by means of 1H and 13C NMR spectroscopy revealed that allyltrimethylsilane rather act as a chain transfer agent in the copolymerization, even though considerable amount of allyltrimethylsilane was incorporated in the polymer chain with rac-Et(Ind)2ZrCl2 catalysts. The chain transfer reaction influence strongly the molecular weight and comonomer content of the copolymers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050619
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Poly[N-(hydroxyethyl)ethyleneimine-co-phenyl succinic anhydride] Synthesis and structure (1999)
    Springer
    Polymer bulletin 43 (1999), S. 341-347 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Five copolymers from N-(hydroxyethyl)ethyleneimine as nucleophilic monomer and phenylsuccinic anhydride (PhSAn) as electrophilic monomer, were synthesized according to the spontaneous copolymerization concept. These copolymers were characterized by elemental analysis, FT-IR, 1H-NMR, and 13C-NMR spectroscopy. The copolymer composition determined from the 1H-NMR spectra showed that the copolymers are not alternating. According to all the data, it was suggested a copolymer structure which includes ester and anhydride bonds. The molecular weights determined by vapor pressure osmometry ranged between 5.100 and 6.100 g/mol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050620
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Comparison of the photopolymerization kinetics of triethyleneglycol dimethacrylate initiated by camphorquinone/N-phenylglycine and camphorquinone/D,L-α-phenylglycine (1999)
    Springer
    Polymer bulletin 43 (1999), S. 349-355 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary This work describes the kinetics of triethyleneglycol dimethacrylate (TEGDM) polymerization, photoinitiated by camphorquinone (CQ) / N-phenylglycine (NPG) and CQ /D,L α-phenylglycine (α-PG), in air and/or in N2. The rates of polymerization (Rp), double bond conversion (p), monomer conversion (pmax), at different concentration of NPG and α-PG were measured and analysed. It was found that CQ/NPG is much more effective photoinitiator system than CQ/α-PG, regarding to the different their chemical structure and H-atom donor ability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050621
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Thermal properties and flammability of acrylic nanocomposites based upon organophilic layered silicates (1999)
    Springer
    Polymer bulletin 43 (1999), S. 395-402 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Thermal and mechanical properties of poly(methylmethacrylate-co-dodecylmethacrylate) nanocomposites based upon exfoliated organophilic layered silicates, were investigated as a function of the silicate and comonomer content. Layered silicates such as sodium bentonite were rendered organophilic by means of ion-exchanging sodium cations for N,N,N,N-dioctadecyl-dimethyl-ammonium cations. Silicate exfoliation was enhanced by means of 5 and 10 wt.-% dodecyl-methacrylate (LMA) addition to afford translucent reinforced acrylic nanocomposites. In contrast to conventional filled acrylic polymers, only 10 wt.-% organophilic silicate was sufficient to increase Young's modulus from 2200 to 4030 MPa, glass temperature from 72 to 80 °C and degradation temperature from 220 to 256 °C with respect to the neat MMA/LMA (90 wt.-%/10 wt.-%) copolymer. Flammability studies, performed on a cone calorimeter, revealed that the maximum heat release rate of MMA/LMA copolymer nanocomposite decreased from 837 kW/m2 to 566 kW/m2. The nanocomposite morphology was examined by means of transmission electron microscopy (TEM).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050627
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    A synthesis of O-diethylaminoethyl chitosan and its binding ability of cholate and deoxycholate anion in vitro (1999)
    Springer
    Polymer bulletin 42 (1999), S. 25-32 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The aim of this study was to investigate the bile salts adsorption behavior of the diethylaminoethyl (DEAE)-chitosan, in vitro. In order to prepare the DEAE-chitosan, where the DEAE groups are specifically introduced onto 6-OH groups of chitosan with minimal by-product, DEAE-chitin was prepared by reacting chitin with N,N-diethylaminoethyl chloride, and direct N-deacetylation of DEAE-chitin was carried out in 10% of an aqueous sodium hydroxide solution containing sodium borohydride. DEAE chitosan samples were incubated with cholic acid sodium salt and deoxycholic acid sodium salt in a tromethane buffer solution (pH 7.5) for 1 hour, and the bile salts adsorption performances of the samples were examined by HPLC. The modified chitosan samples showed improved bile salts adsorption performances compared to chitosan, and the absorption amount of bile salt to the samples increased with increase in the DEAE groups introduced. In most cases, the adsorption amount of deoxycholate to the samples was greater than that of cholate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050430
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    The ambient temperature synthesis and characterization of bile acid polymers (1999)
    Springer
    Polymer bulletin 42 (1999), S. 41-46 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Room temperature polymerization of three naturally occurring bile acids, cholic, lithocholic and deoxycholic, was carried out using a mixture of diisopropyl carbodiimide (DIPC), and a 1:1 salt of dimethyl amino pyridine and p-toluenesulfonic acid (DMAP/PTSA). The corresponding polymers were characterized by IR, NMR, Thermal Analysis and X-ray diffraction. Molecular weights were calculated by gel permeation chromatography in the range 50,000–60,000, using polystyrene standards. The polymers were also characterized by mass spectrometry, using matrix assisted laser desorption ionization-time of flight, MALDI-TOF.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050432
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Synthesis and properties of poly(phenylacetylene)s having dialkylamino groups (1999)
    Springer
    Polymer bulletin 42 (1999), S. 55-60 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Poly(phenylacetylene)s bearing dialkylamino groups were prepared by the polymerization of p-(N,N-dialkylamino)phenylacetylenes with [Rh(nbd)Cl]2, and their electrochemical behavior was examined. Rh-catalyzed polymerization of p-(N,N-diethylamino)phenylacetylene (DEAPA) and p-(N,N-di-n-butylamino)phenylacetylene (DBAPA) in toluene in the presence of triethylamine gave good yields of the polymers (86 and 90%, respectively). Poly(DEAPA) was soluble in chloroform and dichloromethane, and poly(DBAPA) dissolved in various solvents such as toluene, THF, dichloromethane and chloroform. Poly(DEAPA) and poly(DBAPA) showed onset temperatures at 248 and 190°C, respectively, and absorptions around 300–400 nm. Electrochemical doping of the polymer films resulted in the shift of the absorptions to a region around 680 nm, which accompanied a color change of the polymer films from green ocher to deep blue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050434
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Hydrogenation of poly(vinyl cinnamate) thin layer (1999)
    Springer
    Polymer bulletin 42 (1999), S. 149-152 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Hydrogenation of poly(vinyl cinnamate) was performed with RhH(CO)(PPh3)3 catalyst with intent to clarify the photoalignment mechanism of liquid crystals on poly(vinyl cinnamate) alignment layer. The hydrogenated cinnamate side group shows the characteristic peaks at 2.9 ppm and 2.5 ppm in 1H-NMR spectrum, and a decreasing peak at 280 nm in UV spectrum. This reaction can reveal the role of dimerized or residual cinnamate groups in the applications of the polymeric layer for electronic devices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050446
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Ru(0) complex catalyzed polyaddition New synthesis of poly(alkylenebenzoxazole) and poly(alkylenebenzimidazole) (1999)
    Springer
    Polymer bulletin 42 (1999), S. 141-147 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The reactions of α,ω-diyne, HC≡C(CH2)mC≡CH (m = 6 and 8), with 3,3'-diaminobenzidine and with 3,3'-diamino-4,4'-dihydroxybiphenyl in the presence of RU3(CO)12-PPh3 catalyst give the corresponding poly(alkylenebenzoxazole)s and poly(alkylenebenzimidazole)s, respectively. The former polymers obtained from the equimolar reaction of the monomers are partly soluble in polar organic solvents such as DMF, DMSO, and NMP, while the poly(benzimidazole)s are soluble in these solvents. GPC measurement shows the molecular weights of the polymers, M n of 4.8−14.1×103 and M w of 6.4−19.7×103.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050445
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    On the preparation and characterization of chitosan hydrochloride (1999)
    Springer
    Polymer bulletin 42 (1999), S. 159-166 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The procedures for the purification of commercial chitosan samples as hydrochlorides and in the neutralized form are described. Thermal analysis reveals that, independently of the purification method, all samples are highly pure. The agreement between values of degrees of acetylation determined by conductimetric titrations and by 1H nmr spectroscopy is very good. The aqueous solutions of both forms of purified chitosan were free of aggregation as evaluated by their Huggins constants. The potential use of solutions of chitosan hydrochloride in acid-free aqueous NaCl for the studies aiming to characterize the solution behavior of chitosan is demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050448
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Synthesis and properties of nonlinear optical chromophores and polymers containing 6-nitroquinoline as π-electron acceptor (1999)
    Springer
    Polymer bulletin 42 (1999), S. 175-181 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Two nonlinear optical (NLO) methacrylate monomers, 2-methyl-acrylic acid 2-(ethyl-{4-[2-(6-nitro-quinolin-2-yl)-vinyl]-phenyl}-amino)-ethyl ester (5) and 2-methyl-acrylic acid 6-{3-[2-(6-nitro-quinolin-2-yl)-vinyl]-carbazol-9-yl}-hexyl ester (7) were newly synthesized and copolymerized with methylmethacrylate to give NLO polymers, P1 and P2. These polymers were well soluble in organic solvents and showed glass transition temperatures at 145 °C and 114 °C, respectively. The number average molecular weights (Mn) were 26,600 for P1 and 9,300 for P2. The SHG coefficients (d33) of corona-poled films of P1 and P2 measured with 1.064 μm Nd-YAG laser were 32.2 pm/V and 17.6 pm/V, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050450
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    A novel π-conjugated polymer : poly(3,4-bis(phenylene)-3-cyclobutene-1,2-dione) (1999)
    Springer
    Polymer bulletin 42 (1999), S. 183-190 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: ABSTRACT: We have investigated a new 1,2-type aromatic dibromide monomer for preparing a modified π -conjugated poly(p-phenylenevinylene). A novel π -conjugated poly(p-phenylenevinylene) was prepared by dehalogenation polycondensation of a dibromoaromatic compound with a squaric unit as a monomer with zerovalent nickel [Ni(0)] complex. The monomer and the polymer were characterized by FT-IR, 1H-NMR, Elemental Anaylsis, TGA, DSC, GPC and UV-Visible. The resultant polymer had good solubility to polar aprotic, solvents, e.g. DMF, DMAc, DMSO and NMP and solvatochromism in DMAc.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050451
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Mechanochemical synthesis and characterization of poly(vinyl chloride)-block-poly(vinyl alcohol) copolymers by ultrasonic irradiation (1999)
    Springer
    Polymer bulletin 42 (1999), S. 197-204 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Mechanical degradation and mechanochemical reaction in heterogeneous systems of the solid poly(vinyl chloride)-poly(vinyl alcohol) aqueous solutions have been studied by ultrasonic irradiation at 30 °C. The rate of decrease in the viscosity-average degree of polymerization of the degraded poly(vinyl chloride) was much faster than that of the degraded poly(vinyl alcohol). Mechanochemical reaction occurred by free radicals produced from the chain scissions of both polymers by ultrasonic waves. The copolymer was obtained and the molar ratio of the vinyl chloride and the vinyl alcohol units in its copolymer can be determined. In addition, the changes in the composition of the total block copolymer, the unreacted poly(vinyl chloride), and the unreacted poly(vinyl alcohol) were obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050453
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Fracture toughness of polysulfone/epoxy semi-IPN with morphology spectrum (1999)
    Springer
    Polymer bulletin 42 (1999), S. 221-227 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The fracture toughness of the semi-IPN's of crosslinked epoxy and linear polysulfone(PSf) having morphology spectrum was investigated. The epoxy resin was based on diglycidyl ether of bisphenol A(DGEBA) and diaminodiphenylsulfone(DDS). The morphology spectrum, which has the gradual change of the morphological feature resulting from the concentration gradient of PSf in the epoxy resin can be obtained by inserting a PSf film in DGEBA/DDS mixture before cure. The relative rate of the dissolution of the PSf in the epoxy oligomer and the rate of curing reaction determine the concentration gradient of the PSf. In the region where the PSf concentration is less then 5%, sea(epoxy)-island(PSf) morphology is observed. As the concentration of PSf increases, the morphology changes to nodular structure, inverted sea-island, and PSf/epoxy homogeneous phase. Up to overall 10wt% of PSf, the fracture toughness of the PSf modified epoxy with morphology spectrum was higher than that of the counterpart with uniform concentration of PSf. These results were ascribed to the plastic deformation of the continuous PSf rich phase which was present in the morphology spectrum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050456
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Polymerization of allylbenzene with metallocene catalysts (1999)
    Springer
    Polymer bulletin 42 (1999), S. 265-272 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Homopolymerization of allylbenzene was carried out with various metallocene/methylaluminoxane (MAO) catalysts. Different polymerization behavior was observed depending upon the catalysts empolyed. rac-Et(Ind)2ZrCl2 and rac-Me2Si(Ind)2ZrCl2 gave semicrystalline polyallylbenzenes while i-Pr(CpFlu)ZrCl2 and CpTiCl3 did not give any polymeric product. The Cp2ZrCl2 gave amorphous polyallylbenzene with low molecular weight. The effect of temperature on the polymerization was investigated with a constant Al/Zr ratio. The temperature showing maximum catalyst activity is higher for the ansa metallocene catalysts than Cp2ZrCl2 catalyst. The IR and NMR spectra indicated that the polyallylbenzene consisted of allylbenzene repeating unit and no isomerization occurred.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050462
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Synthesis of poly(ethyl vinyl ethers) containing two dipolar electronic systems and their properties (1999)
    Springer
    Polymer bulletin 42 (1999), S. 237-244 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary 5-Nitro-2-(2′-vinyloxyethoxy)benzylidenemalononitrile (2a), methyl 5-nitro-2-(2′-vinyloxyethoxy)benzylidenecyanoacetate (2b), 3-nitro-4-(2′-vinyloxyethoxy)benzylidenemalononitrile (4a), and methyl 3-nitro-4-(2′-vinyloxyethoxy)benzylidenecyanoacetate (4b) were prepared by the condensation of 5-nitro-2-(2′-vinyloxyethoxy)benzaldehyde (1) and 3-nitro-4-(2′-vinyloxyethoxy)benzaldehyde (3) with malononitrile or methyl cyanoacetate, respectively. Vinyl ether monomers 2a-b and 4a-b were polymerized with boron trifluoride etherate as a cationic initiator to yield poly(vinyl ethers) 5-6 having nitrooxybenzylidenemalononitrile and nitrooxycyanocinnamate, which is effective chromophore for second-order nonlinear optical applications. Polymers 5-6 were soluble in common organic solvents such as acetone and DMSO. T g values of the resulting polymer were in the range of 70–81°C. Electrooptic coefficient (r33) of the poled polymer films were in the range of 19–27 pm/V, which was improved by introducing of nitro group. Polymers 5–6 showed a thermal stability up to 300°C in TGA thermograms, which is acceptable for NLO device applications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050458
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Coupling reactions of activated oligo(ɛ-caprolactone)s (1999)
    Springer
    Polymer bulletin 42 (1999), S. 257-264 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Oligo(ɛ-caprolactone)s functionalised with acid groups were prepared by reacting hydroxyl terminated oligo(ɛ-caprolactone)s with succinic anhydride, maleic anhydride or glutaric anhydride. Quantitative conversion of the hydroxyl functionality was achieved in the melt at 130 °C. The resulting acid terminated oligo(ɛ-caprolactone)s were characterised by 1H and 13C NMR spectroscopy. The reactivity of these oligomers was enhanced by conversion of the acid functionality in an acid chloride functionality using thionyl chloride or an anhydride functionality using acetic anhydride. It was shown that these activated oligo(ɛ-caprolactone)s can be used for coupling reactions with compounds containing alcohol- or amino functionalities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050461
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Novel non-alternating copolymers synthesized by spontaneous copolymerization of p-chlorophenylmaleimide with 2-methyl-2-oxazoline (1999)
    Springer
    Polymer bulletin 42 (1999), S. 281-286 
    Details
    ISSN: 1436-2449
    Keywords: Keywords: Nucleophilic and electrophilic monomers; spontaneous copolymerization; non-alternating copolymers.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The copolymerization of p-chlorophenylmaleimide (1) as electrophilic monomer with 2-methyl-2-oxazoline (2) as nucleophilic monomer without initiator in solution under different experimental conditions was investigated. Copolymers were characterized by FT-IR and 1H-NMR spectroscopy. The copolymer composition was determined from 1H-NMR spectra. Molecular weights ranged between 1700 and 5400 g/mol by vapor pressure osmometry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050464
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Study on the alcoholysis of aromatic polyesters and related esters using a high-pressure calorimeter (1999)
    Springer
    Polymer bulletin 42 (1999), S. 295-300 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The heat of base-catalyzed alcoholysis of poly(ethylene terephthalate) (PET) and poly(ethylene 2,6-naphthalenedicarboxylate) (PEN) as well as several related aromatic and aliphatic esters has been measured using a high-pressure calorimeter. The process is essentially thermoneutral, and heats of CH3ONa-catalyzed methanolysis of PET and PEN are +1.8±0.6 and +9.3±0.2 kJ/mol-carboxyl group, respectively. Furthermore, the heats of Zn(OCOCH3)2-catalyzed alcoholysis of PET with ethylene glycol and benzyl alcohol are also calculated as +5.8±0.2 and +6.6±0.8 kJ/mol-carboxyl group, respectively. These values are comparable to those for ethyl esters of p-substituted benzoic acids and propionic acid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050466
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Chain transfer reactions in metallocene catalyzed polymerization of allylbenzene (1999)
    Springer
    Polymer bulletin 42 (1999), S. 301-307 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Allylbenzene was polymerized in the presence of two types of homogeneous zirconocene catalysts (co-catalyst methylaluiminoxane). Selective chain termination through β-hydride elimination or chain transfer to aluminum was observed depending upon the catalysts employed. The rac-Et(Ind)2ZrCl2, and rac-Me2Si(Ind)2ZrCl2, catalysts gave the polyallylbenzenes with saturated end groups due to chain transfer to aluminum, while the Cp2ZrCl2 catalyst gave the polyallylbenzenes with vinylidene end groups due to β-hydride elimination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050467
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Radical polymerization of methacryloyl isocyanate containing 1-adamantanol (1999)
    Springer
    Polymer bulletin 42 (1999), S. 373-378 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Radical polymerization of the methacryloyl isocyanate containing 1-adamantanol (Ad-MAI) with AIBN in different solvents at 60°C was investigated. It is observed that polymerization is slower in polar solvents than in nonpolar ones. The rate of polymerization for Ad-MAI was found to be slower than those of Adph-MAI and MMA both in photopolymerization and in thermal polymerization. Copolymerization of Ad-MAI (M1) with styrene (M2) in benzene was studied at 60°C. The monomer reactivity ratio was calculated to be r1=1.53 and r2=0.76 according to the method of Fineman-Ross. The prominent glass transition temperature for poly(Ad-MAI) was observed at 142°C from global TSC spectrum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050478
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Comb-shaped chitosan derivatives having oligo(ethylene glycol) side chains (1999)
    Springer
    Polymer bulletin 42 (1999), S. 387-393 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Monoaldehydes have been synthesized from tri- and tetra(ethylene glycol) monosubstituted derivatives and introduced into chitosan by the reductive alkylation technique to give comb-shaped polysaccharide hybrids. The reaction of chitosan with the aldehydes in the presence of sodium cyanoborohydride proceeded efficiently to give chitosan derivatives having oligo(ethylene glycol) side chains at the amino groups. The products were characterized by high affinity for organic solvents as well as water in sharp contrast to the original chitin and chitosan. They showed significant adsorption capacity toward metal cations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050480
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Synthesis and properties of nonlinear optical polymers based on poly(ether imides) for electrooptical devices (1999)
    Springer
    Polymer bulletin 42 (1999), S. 403-409 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary : Nonlinear optical poly(ether imides) with an adequate thermal stability has been synthesized by direct coupling of hydroxy poly(ether imides) and NLO chromophores with a quantitative yield. The resultant amorphous NLO poly(ether imides) exhibited good solubility in common organic solvents, providing optical-quality thin films by spin coating. The glass transition temperatures of the polymers are at around 180 °C. The electrooptic coefficients (r33, @1.3μm) of PEI-DR1 was 12.3 pm/V with an electrical poling field of 100 V/μm and it decayed about 10 % over 10 months at 90 °C under atmospheric conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050482
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    A novel gas sensor from crystalline polymer-grafted carbon black: responsibility of electric resistance of composite from crystalline polymer-grafted carbon black against solvent vapor (1999)
    Springer
    Polymer bulletin 42 (1999), S. 425-431 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Crystalline polymers, such as poly(ɛ-caprolactone) (PCL), poly(ethylene adipate) (PEA), and polyethylene (PE), were successfully grafted onto carbon black surface by direct condensation of terminal groups of these polymers with carboxyl groups on the surface using N,N'-dicyclohexylcarbodiimide as a condensing agent. The electric resistance of a composite prepared from these crystalline polymer-grafted carbon black drastically increased to 104–105 times of initial resistance in good solvent vapor of grafted polymer and returned to initial resistance when it was transferred into dry air. However, the change of electric resistance of the composite hardly observed in poor solvent vapor. These results suggest that these composite can be applied as a novel gas sensor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050485
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Corona poling of liquid crystalline polymers with nitroazobenzene side chains (1999)
    Springer
    Polymer bulletin 42 (1999), S. 575-578 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The orientational behavior of liquid crystalline polymers with para-nitro azobenzene as side chains under electric field was studied by UV-visible spectroscopy. The results showed that λmax of the poled polymer films was around 394nm, compared to that of the unpoled films, the absorption decreased due to poling. The orientational parameters increased linearly with the increase of the electric field. The temporal stability of the poled polymer film is good at room temperature. This kind of materials showed promise application as nonlinear optical component in photorefractive polymers
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050504
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Rheo-optical fourier transform infrared spectroscopy of diol-modified diglycidyl ether of bisphenol-A epoxy resins (1999)
    Springer
    Polymer bulletin 42 (1999), S. 579-586 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The molecular orientation behaviour of epoxy networks on the basis of the diglycidyl ether of bisphenol-A (DGEBA) and various linear aliphatic diols was studied by rheo-optical FTIR spectroscopy. Uniaxial deformation was performed above and below the glass transition temperature. The influence of diol chain length and molar ratio on the mechanical properties and the orientation parameter will be discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050505
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Electro-optic studies on novel chiral liquid crystalline polysiloxanes with the N* phase (1999)
    Springer
    Polymer bulletin 42 (1999), S. 603-609 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The electro-optical response of two novel side chain liquid crystalline polysiloxane copolymers containing chiral pendant groups was investigated. It was found that both copolymers possessed N* phase with a long pitch and therefore the origin of the electro-optical response detected in this phase was considered to be the electroclinic effect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050508
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Novel blends of alternating propene-carbon monoxide copolymers and styrenic copolymers (1999)
    Springer
    Polymer bulletin 42 (1999), S. 611-618 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Alternating propene-carbon monoxide copolymers (P-CO) were melt-blended with polystyrene, poly(styrene-co-acrylonitrile) (SAN), and with poly(styrene-co-maleic anhydride) (SMA). P-CO forms homogeneously miscible blends with SAN containing 25 wt% AN at the investigated blend compositions. The transparent blends have single, intermediate glass transition temperatures that fit the Fox equation. The elastic properties of P-CO at room temperature disappear upon blending with SAN because the T g is driven above RT. Polystyrene and SMA are not miscible with P-CO and form heterogeneous blends with two glass transitions. This demonstrates that both the polarity of the styrenic copolymer and the nature of the comonomer govern its phase behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050509
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Polymerization of methyl methacrylate using organocalcium compounds (1999)
    Springer
    Polymer bulletin 42 (1999), S. 635-639 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary We have studied the polymerization of methyl methacrylate (MMA) using biscyclopentadienylcalcium (Cp2Ca) and bis(pentamethylcyclopentadienyl)calcium (Cp2 *Ca) as initiators. Polymerizations initiated with CP2Ca produced poly(methyl methacrylate), PMMA, with %rr = 80. This polymerization was conducted in 1,2-dimethoxyethane at 0°C; monomer conversion was 57% after 19 h. Lindsell and co-workers reported a much higher syndiotacticity for the same initiator. While 80%rr is higher than a free radical polymerization of MMA at the same temperature, the broad polydispersity and low conversions make this polymerization method unattractive. Use of the more soluble initiator Cp2 *Ca significantly increases monomer conversion but produces PMMA with lower syndiotacticity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050512
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Cationic photopolymerisation of divinylethers systems containing hydroxyvinylethers (1999)
    Springer
    Polymer bulletin 42 (1999), S. 641-648 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Diethyleneglycoldivinylether (DVE2) and triethyleneglycoldivinylether (DVE3) were photopolymerised together with monovinylethers and hydroxyalkylvinylethers, in order to study the curing reaction and to evaluate the properties of the films obtained. In the presence of the monovinylethers, the flexibility of the cured films increased and the Tg values decreased. In the presence of a hydroxyalkylvinyl ether, a stronger plasticisation effect was obtained and attributed to a chain transfer reaction involving -OH groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050513
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Synthesis of Congo Red linked with alkyl amide polymer and its optical ion-sensing property (1999)
    Springer
    Polymer bulletin 42 (1999), S. 655-660 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The synthesis and metal ion responsive properties of Congo Red-based polyamide are reported. The polymer was prepared by simple interfacial polymerization between Congo Red and sebacoyl chloride. The polymer showed decrease in electronic absorption when exposed to metal ions. The absorbance tends to decrease linearly in a measurable range according to metal ion concentration. It is found that the polymer showed high sensitivity toward Ca2+ and Fe3+.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050515
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Synthesis and properties of poly(amide-imide)s with different microstructures based on trimellitimide and 4,4'-diphenyl ether (1999)
    Springer
    Polymer bulletin 42 (1999), S. 661-668 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Poly(amide-imide)s(PAIs) with different microstructures were prepared based on trimellitimide and 4,4'-diphenylether with varying the reaction conditions. The microstructures of PAIs were examined by 500MHz 1H-NMR spectroscopy. The head-to tail (HT-) PAI showed a sharp peak in WAXD curve, a large shift at around 1670 cm−1 for −C=O stretching in FT-IR spectra, and poor solubility in organic solvents, high density, Tg, tensile strength and modulus compared to head-to-head (HH-) PAI and copolymers of HT and HH. These results might be due to the higher packing tendency of the HT PAI than HH PAI or copolymers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050516
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Synthesis of conjugated polyphenylacetylenes with redox active ferrocenyl end-groups (1999)
    Springer
    Polymer bulletin 42 (1999), S. 683-688 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Metathesis polymerization has been employed for the synthesis of polyphenylacetylene (PPA) containing redox-active ferrocene groups at both ends. Two reversible one electron oxidation waves were detected in CV. The ΔE values decreased with increase in chain length of the polymer, indicating that the metal-metal interaction decreases by increasing the chain length.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050519
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Preparation and sensor properties of poly (o-toluidine) film (1999)
    Springer
    Polymer bulletin 42 (1999), S. 693-699 
    Details
    ISSN: 1436-2449
    Keywords: Key Words: poly(o-toluidine); enzyme electrode; amperometric biosensor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary An amperometric biosensor for glucose was constructed in a one-step procedure by the electropolymerization of o-toluidine in the presence of glucose oxidase on Pt substrates in KCl aqueous electrolyte at a potential of 0.5 V vs Ag / AgCl. The amperometric responses of the prepared polymeric biosensor to the glucose were measured at a potential of 0.7 V in PBS solution. Results showed that this polymeric sensor exhibited a fast amperometric response time (4–5 s) and a linear range up to 6 mM glucose with poor stability. Also, it was seen that biosensor responded successfully to glucose injections in the presence of some interfering species such as lactose, sucrose and urea.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050521
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Study of the miscibility of poly(ethyl methacrylate-co-4-vinylpyridine)/poly(styrene-co-cinnamic acid) blends (1999)
    Springer
    Polymer bulletin 42 (1999), S. 701-708 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The miscibility of a series of poly(ethyl methacrylate-co-4-vinylpyridine) with poly(styrene-co-cinnamic acid), is investigated by differential scanning calorimetry. The results show that each blend is miscible as ascertained by a single composition dependent glass transition temperature. The Tg's of the blends exhibit positive deviations from the weight average Tg's of the blend components. The thermograms data exploited according to the Kwei and Schneider approaches suggest the occurrence of strong specific intermolecular attractive interactions within the binary systems. The strength of these interactions, as estimated from the Kwei q-values, increases with the proton donor and proton acceptor contents in the copolymers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050522
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Thermosensitive networks based on high molecular weight polyoxyethylene and N-isopropylacrylamide (1999)
    Springer
    Polymer bulletin 42 (1999), S. 709-716 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary γ- and UV-irradiation was successfully used for the preparation of mixed networks on the basis of high molecular weight polyoxyethylene (POE) and/or N-isopropylacrylamide and poly(N-isopropylacrylamide) (PNIPAAm). These gels preserve the swelling transition temperature of the pure PNIPAAm and shrink faster above this temperature due to the hydrophilic POE chains. It was found that in a collapsed state these gels retain alkaline organic salts from aqueous solutions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050523
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Solid particle erosion of electrically insulating silicon and EPDM rubber compounds (1999)
    Springer
    Polymer bulletin 42 (1999), S. 717-724 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Jet erosion tests of outdoor insulating silicone and EPDM rubbers were carried out by means of a modified sandblasting equipment. The presence of relatively large, non-reinforcing filler particles increased the erosion rate of the silicone rubber compounds. The erosive wear of highly filled compounds strongly depended on the incident angle of the eroding particles. Rubbers with low amount or very finely dispersed reinforcing filler showed a good resistance to solid particle erosion. The mechanisms of material removal were studied by scanning electron microscopy and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050524
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Polymerization of cyclic monomers 9. Synthesis and radical polymerization of spirocyclic 2-vinylcyclopropanes (1999)
    Springer
    Polymer bulletin 43 (1999), S. 1-7 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary 6,6-Diethyl- (1a) and 6-methyl-6-propyl-5,7-dioxa-4,8-dioxo-1-vinylspiro[2.5]octane (1b) were synthesized by the acetalization of 2-vinylcyclopropane-1,1-dicarboxylic acid with 2- or 3-pentanone. The new monomers were characterized by IR, 1H NMR and 13C NMR spectroscopy. The radical polymerization of the monomers 1a and 1b, in addition of 6,6-methyl-5,7-dioxa-4,8-dioxo-1-vinylspiro[2.5]octane (1c) and (exo/endo)-7-ethoxycarbonyl-2-oxo-7-vinyl-bicyclo[4.1.0]heptane (1d), was carried out in bulk with 2,2`-azoisobutyronitrile (AIBN) as the initiator. The polymer yield with 1d was only low. The polymerization of the monomers 1a and 1c resulted in cross-linked polymers, whereas in case of the polymerization of monomer 1b soluble polymers in a high yield were obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050525
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Synthesis of a star-shaped polymer by coordination of 2,2'-bipyridyl-terminated poly(propylene glycol) with ruthenium ion (1999)
    Springer
    Polymer bulletin 43 (1999), S. 9-12 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The Ru(II)-centered star-shaped polymer was prepared by coordination of 2,2'-bipyridyl-terminated poly(propylene glycol) with ruthenium ion. The structure was confirmed by GPC analysis and UV/Vis spectrum. The resulting polymer complex was well-soluble in various organic solvents and water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050526
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Synthesis and properties of poly(p-phenylenevinylene-co-sulfonylene) for a blue light-emitting diode (1999)
    Springer
    Polymer bulletin 43 (1999), S. 13-20 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Novel class of p-phenylenevinylene copolymer with sulfonylene group in the main chain (PPVS) was synthesized through the Wittig reaction of bis(bromomethyl-p-phenyl)-sulfone triphenylphosphonium salt with terephthaldehyde. PPVS was highly soluble in common organic solvents and showed strong blue-shifted fluorescence because the polar sulfonylene group provided better solubility and limited π-conjugation in polymer chain. A single layer device with PPVS sandwiched between indium-tin-oxide (ITO) and aluminum electrodes showed a blue electroluminescence (EL) peaked at 470 nm under the threshold voltage of 14 V. HOMO and LUMO levels of PPVS were found to be 0.46 and 0.28 eV, respectively, lower than those of poly(p-phenylenevinylene) (PPV).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050527
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Polyelectrolyte complex between chitosan and poly(2-acryloylamido-2-methylpropanesulfonic acid) (1999)
    Springer
    Polymer bulletin 43 (1999), S. 67-73 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary A new polyelectrolyte complex between chitosan and poly(2-acryloylamido-2-methylpropanesulfonic acid) (PAMPS) was prepared by mixing aqueous solutions of its components or by free radical polymerization on chitosan template. The complex formation was sensitive to the ionic strength of the medium. The complex was stable in acidic and neutral medium and dissociated at pH 〉 8. Its composition did not depend on pH values of the medium and the way of preparation. The mixing dilute aqueous solutions of chitosan and PAMPS resulted in the formation of nanoparticles with mean particle diameter 250 nm and monomodal distribution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050534
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    A method for comparing the nucleation ability of PTFE, iPP and sPP on PE (1999)
    Springer
    Polymer bulletin 43 (1999), S. 75-80 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: SUMMARY Heterogeneous nucleation is not only a commonly encountered phenomenon of polymer crystallization, but also a fundamentally important research topic for understanding polymer crystallization. Both, polymer epitaxy and transcrystallization are well known mechanisms for surface induced oriented nucleation, but they only have been studied separately with respect to the nucleation abilities of one polymer to another. A new experimental procedure is established to combine transcrystallization and heteroepitaxy of one polymer on two different polymeric substrates. This provides a new way for comparing the relative nucleation onset of one polymer nucleated simultaneously onto two different substrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050535
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Assignment of 13C NMR chemical shift and microstructure of copolymers of 2-chloroethyl vinyl ether-maleic anhydride and n-butyl vinyl ether-maleic anhydride (1999)
    Springer
    Polymer bulletin 43 (1999), S. 81-85 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The chemical shift in the 13C NMR spectra of copolymers of 2-chloroethyl vinyl ether (CEVE) and maleic anhydride (MA), and of n-butyl vinyl ether (BVE) and MA is assigned. It is found that both copolymers are made of completely alternating monomer unit sequences and that the proportion of cis linkage configuration at the cyclic MA units is 45 % and 47 % in the CEVE-MA copolymer and in the BVE-MA copolymer, respectively. Depending on the relative orientation of the cyclic anhydride group, quasi “isotactic” and quasi “syndiotactic” tacticity are considered, with quasi “syndiotactic” diads shielding the vinyl ether carbons more effectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050536
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    IRS study of ethylene polymerization catalyst SiO2/MAO/zirconocene (1999)
    Springer
    Polymer bulletin 43 (1999), S. 87-92 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Lewis acidic sites (LAS) of silica, modified with TMA and MAO samples differed by TMA content, have been characterized by IR spectroscopy (CO adsorption as probe molecule at 77 K). Two types of LAS were found on the surface of silica modified with MAO and TMA: M LAS of moderate strength (νCO= 2204−2212 cm−1) and weak W LAS (νCO= 2194 cm−1). The concentration of these acidic sites has been estimated. It was shown by IRS study Cp2ZrMe2 interacts both with W LAS and M LAS. Correlation between the amount of M LAS and the activity of ethylene polymerization has been found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050537
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Lithographic results of electron beam photoresists prepared by living free radical polymerization (1999)
    Springer
    Polymer bulletin 43 (1999), S. 93-100 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary A new family of random copolymers composed of chloromethylstyrene and a silicon based styrenic monomer was prepared using living radical polymerization. The lithographic efficiency of the resulting electron beam resists was examined. A pronounced improvement on the lithographic resolution and image quality of resists with a narrow molecular mass distribution was observed and is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050538
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Chitosan gel beads as drug carriers 2. Release of 8-hydroxy-7-iodoquinoline-5-sulfonic acid and 2,5-dihydroxybenzenesulfonic acid (1999)
    Springer
    Polymer bulletin 43 (1999), S. 101-107 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary It is shown that chitosan gel beads are suitable carriers of 8-hydroxy-7-iodoquinoline-5-sulfonic acid (SQ) and 2,5-dihydroxybenzenesulfonic acid (DHBSA) - substances applied in medicine. Drug release has been investigated with respect to the nature of the crosslinking agent (epichlorohydrin or glutaraldehyde) and pH of the medium. Considerable differences in the release rate of DHBSA and SQ have been found. The total amount of the desorbed SQ, as well as the release rate of the drug depends on pH of the medium - they decrease from alkaline to acidic medium. The antimicrobial and antimycotic activity of the loaded with SQ beads is demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050539
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Alternating boration copolymerization between diyne and bisallene (1999)
    Springer
    Polymer bulletin 43 (1999), S. 117-120 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Alternating boration copolymerization between 1,4-diallenylbenzene (2) and 2,7-diethynylfluorene (3) was examined using diphenylbromoborane (1) to give the corresponding copolymer (4). The organoboron copolymer obtained was characterized by 1H-, 11B-NMR, IR, and UV-vis absorption spectra.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050541
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Controlled radical polymerization of styrene utilizing excellent radical capturing ability of diphenyl ditelluride (1999)
    Springer
    Polymer bulletin 43 (1999), S. 143-150 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The radical polymerization of styrene was investigated in the presence of diphenyl ditelluride (DPDTe) under varied conditions. In the polymerization without any radical initiator at higher temperature (125°C), the addition of DPDTe surely decreased the polymer molecular weight (M n) while the polydispersity (M w/M n) was rather broad. The polymerization with benzoyl peroxide (BPO) as the initiator was also uncontrollable to afford polymers with broad M w/M n probably due to the redox side reaction of BPO with DPDTe. On the contrary, the precision control of M n and the initiating end structure could be achieved by the polymerization with 2,2'-azobisisobutyronitrile (AIBN), that is, M n increased in proportion to the molar ratio of monomer to initiator suggesting the suppression of bimolecular chain termination reactions by the excellent radical capturing ability of DPDTe.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050545
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Phase transition in swollen gels 27. Effect of negative charge concentration on swelling and mechanical behaviour of poly(N-vinylcaprolactam) gels (1999)
    Springer
    Polymer bulletin 43 (1999), S. 109-116 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Ionized networks of copolymers of N-vinylcaprolactam with charged comonomer, sodium itaconate (mole fraction of ionic comonomer xs= 0−0.1) and of a crosslinker, 3,3'-(ethane-1,1-diyl)bis(1-vinyl-2-pyrrolidone) were prepared by radiation polymerization in water/ethanol mixture (H2O/Et = 0.3/0.7 by vol.) and their swelling; mechanical behaviour in water was investigated as a function of temperature. On heating, a decrease in the swelling degree was observed. Increasing xs shifts the volume transition temperature Ttr from the swollen to shrinked state to higher temperatures; in all cases, this transition is continuous. The observed decrease in swelling with temperature is accompanied by an increase in equilibrium modulus, so that mechanical behaviour is predominantly determined by swelling. The swelling of hydrogels can be in the first approximation described by the theory of polyelectrolyte networks in which repulsion of charges on the chain and finite chain extensibility were considered. In accord with this theory, as the Flory-Huggins interaction parameter χ= 0.522 for the uncharged network swollen in water, no jumpwise change in volume with increasing temperature was observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050540
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Living polymerization of hexaethylcyclotrisiloxane (1999)
    Springer
    Polymer bulletin 43 (1999), S. 129-134 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Living polymerization of hexaethylcyclotrisiloxane was achieved with nBuLi-(nBuO)3PO at room temperature to produce living poly(diethylsiloxane). The molecular weight of the polymer increased in direct proportion to monomer conversion and to the reciprocal to the initial nBuLi concentration. Molecular weight distribution remained 1.1–1.2 during the polymerization. The polymerization was completed only after 1 day despite no solvent was used. When a compound containing SiOH groups was added to the polymerization system, the number of polymer chain agreed with a sum of nBuLi and SiOH groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050543
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Coupling and linking reactions of living polyisobutylene by allylsilanes (1999)
    Springer
    Polymer bulletin 43 (1999), S. 121-128 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The reactions of living polyisobutylene (PIB+) with different allylsilanes, as potential linking and coupling agents, have been studied. Quantitative monoaddition of 2-Phenylallyltrimethylsilane to living PIB+ yielded macromonomer (I), however coupling was absent. Rapid and quantitative coupling has been observed with 1,3-bis[2-(3-trimethylsilyl)-propenyl]benzene (bTPB). Using 1-(2-propenyl)-3-[2-(3-trimethylsilyl)-propenyl]benzene (PTPB) star polymers with an average of four arms have been prepared with high efficiency. The study of this linking reaction revealed that star formation takes place in two well separated steps. In the first step a macromonomer is formed in situ by the rapid reaction of PIB+ with the allyltrimethylsilyl functionality. Subsequent reaction of this macromonomer with the remaining electrophilic PIB+ ends followed by interchain reactions results in the formation of star polymers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050542
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Synthesis of poly(cyclodiborazane)s by hydroboration polymerization of dicyano compounds with tripylborane (1999)
    Springer
    Polymer bulletin 43 (1999), S. 151-155 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Hydroboration polymerizaton of dicyano compounds was examined by using tripylborane, which is known as a fairly stable hydroborating agent, to give the corresponding poly(cyclodiborazane)s in good yields. The number average molecular weights of the obtained polymers were in the range of several thousands. These polymers exhibited high stability toward air and moisture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050546
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Synthesis and characterization of partially crosslinked poly(N-vinylcarbazole-vinylalcohol) copolymers with polypyridyl Ru(II) luminophores: Potential materials for electroluminescence (1999)
    Springer
    Polymer bulletin 43 (1999), S. 135-142 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary A novel difunctionalized 5,5'-dibromomethylene-2,2' bipyridine ligand was prepared and covalently bound with concurrent crosslinking by a post-polymer modification method to (N-vinylcarbazole-vinylalcohol) copolymer. The electrochemistry and UV-vis spectroscopy results both confirm the covalent attachment of ruthenium transition metal complex to the polymer backbone. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) indicate high thermal stability of the copolymer. The copolymer is also highly phosphorescent making it a potential polymeric material for transition metal based electroluminescent devices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050544
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Metal ion extraction behavior of poly([2(methacryloyloxy)ethyl]trimethylammonium chloride-co-acrylic acid) resin (1999)
    Springer
    Polymer bulletin 43 (1999), S. 277-283 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: SUMMARY The crosslinked poly([2-(methacryloyloxy)ethyl]trimethyl ammonium chloride-co-acrylic acid) was tested as adsorbent for Cd(II), Hg(II), Zn(II), Pb(II), Cr(III), and U(VI) by batch equilibrium procedure. At pH 5.0 the adsorbent retained 74% (1.865 meq/g) of U(VI) with a maximum capacity of load of 2.7 meq/g (108 mg/g). The resin-U(VI) equilibrium was achieved around of 1 h which is considered adequate for a heterogeneous reaction. It showed a high selectivity for U(VI) respect to all the other metal ions both from competitive and non-competitive conditions. The recovery of the resin was over 65% by H2SO4 and Na2CO3.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050563
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Crystallization in blends of isotactic polypropylene with polyethylene-b-poly(ethylene-co-butylene)-b-polyethylene block copolymer (1999)
    Springer
    Polymer bulletin 43 (1999), S. 285-289 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract In this study, isothermal crystallization in blends of isotactic polypropylene (i-PP) with polyethylene-b-poly(ethylene-co-butylene)-b-polyethylene block copolymer (CEBC) was investigated using a polarized photometer, polarized microscope and differential scanning calorimeter. Half time of crystallizaiton (τ1/2) is increasing with increasing CEBC content in i-PP/CEBC blends. Avrami index and rate constant of crystal growth decrease with increasing CEBC content in i-PP/CEBC blends. On the contrary, heat of fusion of i-PP crystal in the blends is almost constant against the variation of CEBC content in i-PP/CEBC blends. Hence, it is pointed out that blending i-PP with CEBC caused only retardation of rate of crystalline growth and change in mechanism of crystalline growth from three dimensional to two dimensional growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050564
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Synthesis of polyisoprene-poly(methyl methacrylate) block copolymers by using polyisoprene as a macro-iniferter (1999)
    Springer
    Polymer bulletin 43 (1999), S. 327-332 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Polyisoprene (PI) was pre-polymerized by using benzyl diethyldithiocarbamate (BDC) as an iniferter. The obtained PI was subsequently used to react with methyl methacrylate (MMA) in order to investigate whether the relevant block copolymers can be achieved. Results from 1H-NMR and GPC reveal that the PI-PMMA block copolymers were formed. This suggests that polymerization of isoprene through the use of BDC proceeded via a (psuedo) “living” mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050618
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Morphology of fibers formed via thermally induced phase separation of polypropylene and liquid paraffin blend in stress-field (1999)
    Springer
    Polymer bulletin 43 (1999), S. 291-296 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Phase diagram obtained from small angle light scattering (SALS) and differential scanning calorimetry (DSC) of polypropylene/liquid paraffin blend system indicates that the melts undergo solid-liquid phase separation upon cooling and liquid paraffin is expelled out of crystalline region of polypropylene. Fibers spun under high take-up draw ratio are found to be hard-elastic. Long periods in the meridional direction are observed on the curves of small angle X-ray scattering (SAXS), and the yield point of fibers decreases with the increase in liquid paraffin content, which indicates such fibers have row-nucleated lamellar structure perpendicular to the fiber direction. The feasibility of preparing microporous membranes by stretching such fibers is investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050565
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    High resolution solid state 13C NMR investigation of the deoxycholic acid / ferrocene inclusion compound (1999)
    Springer
    Polymer bulletin 43 (1999), S. 365-369 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The molecular mobility of deoxycholic acid (DCA) / ferrocene inclusion compound has been investigated by high resolution solid state 13C NMR spectroscopy. Compared to the single crystal of ferrocene, the molecular mobility of the ferrocene in the inclusion compound is enhanced because it is included in the large cavity of DCA. It is found that the relaxation time measurement by solid state 13C NMR can provide powerful evidence to confirm the formation of the inclusion compound.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050623
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Study on the interaction of diarylbutadiynes with free radicals: Interaction with propagating radicals of some vinyl monomers (1999)
    Springer
    Polymer bulletin 43 (1999), S. 357-364 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract In order to study the nature of interaction of arylbutadiynes with transient free radicals, polymerization and copolymerization of some vinyl monomers such as methyl methacrylate (MMA), styrene (ST), methacrylonitrile (MAN), vinylidene chloride (VCl2), ethyl acrylate (EA) and acrylonitrile (AN), were carried out in the presence of diphenylbutadiyne (DPB), 4,4'-butadiynylene-N,N,N',N'-tetra-n-butyl-dibenzamide (BBA), and 4,4'-dibromodiphenylbutadiyne (BPB). MMA gave an intense ESR signal at the polymerization temperature when the polymerization system became viscous, and the number of radicals increased with polymerization time. Strong signals of polyEA and polyMAN radicals were also observed in the presence of DPB when the polymerization system became almost solid. This is a unique case where active transient propagating radicals such as that of polyEA can be detected at polymerization temperature. The rates of polymerization decreased by the presence of the diacetylenes, but the molecular weights did not change with the diacetylene concentrations. UV spectroscopy revealed that there was no diacetylene unit bonded to the obtained polymers, indicating that degradative chain transfer is not the case. The monomer reactivity ratios for MMA-ST and MMA-AN systems did not vary significantly in the presence of the diacetylenes, although some difference was observed. It seems that some arylbutadiynes interact with free radicals but do not form bonds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050622
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Local order and strain-induced orientation in poly(butadiene) networks studied by 2H NMR (1999)
    Springer
    Polymer bulletin 43 (1999), S. 371-378 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Deuterium nmr has been employed to determine the average orientation of chain segment in poly(butadiene) networks. The nmr spectrum lineshape reveals the orientation distribution of network vectors due to the crosslinks, whereas the observed splitting gives information about the orientation due to segmental interactions. Both the lineshape and the splitting have been fitted simultaneously for a range of deformed poly(butadiene) networks varied in crosslink density and precursor chain length. From the fitting parameters the separate contribution to the average orientation arising from network constraints and interaction are calculated. These are used to estimate the effective molecular weight between topological constraints and the size of the segmental interaction. It could be shown that the latter remains constant as the crosslink density is varied. This is a strong evidence of the recently published theoretical framework.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050624
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Preparation, MALDI-TOF analysis, and micelle-like behavior of alkyl-modified poly(propylene imine) dendrimers (1999)
    Springer
    Polymer bulletin 43 (1999), S. 379-386 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary MALDI-TOF mass spectral analysis was used to characterize the novel unimolecular micelles that result from functionalization of the chain ends of poly(propylene imine) dendrimers with C10 alkanoyl or C12 alkyl groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050625
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Complexes of chitosan and poly(methacrylic acid) studied by fluorescence techniques (1999)
    Springer
    Polymer bulletin 43 (1999), S. 387-394 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Fluorescence techniques have been used to study the interactions of poly(methacrylic acid) (PMAA) with chitosan(CS) in aqueous solution. These studies show that PMAA and CS form complexes within a pH range of 3 to 10 and along with complexing with CS, the conformation of PMAA at pH 4 changed from a hypercoiled to a loose coiled form. However, this conformational change is not complete since the optimal ratio for the complex formation is 0.5:1(CS:PMAA, in residue unit). PMAA/CS complexes at pH 4 were largely disrupted with the addition of NaCl, most likely due to screening of the electrostatic attraction between ionized carboxyl groups of PMAA and protonated amino groups of CS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050626
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Graft polymerization of N,N-dimethylaminoethylmethacrylate onto polycarbonates by the preirradiation method (1999)
    Springer
    Polymer bulletin 43 (1999), S. 403-408 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Radiation-induced graft polymerization of N,N-dimethylaminoethylmethacrylate (DMAEMA) from solutions in carbon tetrachloride or in chloroform onto bisphenol A-derived polycarbonate (PC-1) and allyl diglycol carbonate (PC-2), respectively, was carried out by method of preirradiation in air. It has been found essential difference in transparency and durability of the modified PC-1 and PC-2. Effects of preirradiation dose as well as temperature and time of graft polymerization on effectiveness of DMAEMA grafting onto PC-2 were investigated, the optimal values of dose and temperature are 500 kGy and 55°C, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050628
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Deposition of high fluorine content macromolecular thin layers under continuous-flow-system corona discharge conditions (1999)
    Springer
    Polymer bulletin 43 (1999), S. 409-416 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary High fluorine content macromolecular layers were deposited on polyethylene (PE) film surfaces under an originally designed, continuos-flow-system plasma reactor conditions. Survey and angle resolution, ESCA data and ATR-FTIR results indicate that the plasma-created films are thin and have a fairly uniform structure. The fluorinated layers have a 60% relative fluorine atomic concentration, and are mainly composed of CF2-CF, and C-CF3 groups. AFM images collected from virgin and plasma-exposed PE surfaces show a significantly rougher surface of the plasma-treated substrates. Applications can be envisaged for creating Teflon-like coatings on various polymeric film surfaces using a continuous plasma process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050629
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    On the fine emulsion polymerization of styrene with non-ionic emulsifier (1999)
    Springer
    Polymer bulletin 43 (1999), S. 417-424 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The fine emulsion polymerizations of styrene initiated by a redox system ammonium peroxodisulfate/sodium thiosulfite stabilized by a non-ionic emulsifier were kinetically investigated. The dependence of the rate of polymerization on conversion or the emulsifier concentration was described by a curve with maximum at medium conversion. The maximum rate of polymerization is proportional to the − 0.45th and 1.5th power of initiator and emulsifier concentration, the number of particles to the 0.32nd and 1.3rd power of initiator and emulsifier concentration and the molecular weight to the − 0.62th and −0.97th power of initiator and emulsifier concentration, respectively. The results show a strong decrease in turbidity at around 20% conversion when emulsion turns into translucent latex. Deviation from the micellar nucleation model was attributed to the solubility of emulsifier in monomer, high level of nonmicellar aggregates, thick interfacial layer and transfer emulsion to microemulsion. The strong decrease of molecular weight with increasing emulsifier concentration is attributed to chain transfer events promoted by the high level of emulsifier at the reaction loci.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050630
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Heterogeneities during the formation of poly(sodium acrylate) hydrogels (1999)
    Springer
    Polymer bulletin 43 (1999), S. 425-431 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary In situ fluorescence and light scattering techniques were used to study the formation of heterogeneities during the free-radical crosslinking polymerization of sodium acrylate (NaAc) in the presence of N,N'-methylene(bisacrylamide) (BAAm) as a crosslinker. Pyranine was used as a fluorescence probe in the experiments. The reactions were carried out at room temperature and at a monomer concentration of 20.6 w/v% in water. It was found that the gel forming system became turbid at the start of the reaction; continuing polymerization and crosslinking reactions turned the opaque gels into slightly opaque and finally transparent gels. Two peaks were observed both in the scattered and emitted light intensities versus the reaction time plots. The first peak corresponds to the formation and growth of the phase separated domains whereas the second peak reflects the macrogelation point in the reaction system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050631
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Bilayer films composed of wheat gluten and functionalized polyethylene: Permeability and other physical properties (1999)
    Springer
    Polymer bulletin 43 (1999), S. 441-448 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Bilayer films composed of a wheat gluten layer and a functionalized polyolefin film were performed by hot press process with the aim to improve the moisture barrier property of hydrophilic gluten films. An ethylene/acrylic ester/maleic anhydride terpolymer (Lotader 3410) and an ethylene/glycidyl methacrylate copolymer (Lotader GMA) were used. The use of both Lotader products had no incidence on film opacity, and was effective to reduce dispersion in water and water vapor permeability. In the presence of the terpolymer, the mechanical properties were enhanced and the wide range selectivity of gluten films was preserved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002890050633
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Review and Classification of Corneal Topographers (1999)
    Springer
    Lasers in medical science 14 (1999), S. 2-19 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Corneal topography; Fluorescence; Holography; Interferometry; Moiré; Partial coherence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. Corneal topography has, due to developments in refractive surgery and contact lens fitting, become a widely used diagnostic tool. Many types of topographers have been introduced, but there is some confusion on classification and subsequent principal possibilities of the various devices offered to the practitioner. The purpose of the study reported here was to make an inventory of developed devices, analyse the basic principles and create a classification based on optical principles. A literature search was done using Medline, the IBM Patent Server, and references found in articles and patents. This search resulted in a variety of descriptions that could be classified into 12 groups according to their use of light source and light-matter interaction of which four groups have representatives on the commercial market. This classification can be used by researchers and practitioners to gain insight into the possibilities of a given device in relation to the desired application.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050015
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Diffusing Fibre Tip for the Minimally Invasive Treatment of Liver Tumours by Interstitial Laser Coagulation (ILC): An Experimental Ex Vivo Study (1999)
    Springer
    Lasers in medical science 14 (1999), S. 32-39 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Interstitial laser coagulation; Laser applicator; Laser induced thermotherapy; Liver tumours; Nd-YAG laser
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. A newly developed diffusing laser applicator was examined for interstitial laser coagulation (ILC) of liver tumours. The applicator consisted of a matted quartz core and a quartz glass dome, also matted on its inner surface and sealed to the fibre. The applicator provided a homogeneous light intensity distribution over an active length of about 20 mm. Lesions were created in an ex-vivo porcine liver model using a Nd-YAG laser comparing the new diffusing tip with a Ringmode®-ITT applicator in order to find optimal laser parameters and damage thresholds. The lesions were investigated using macroscopic size measurement, volume calculation and histological examination (H&E, NADPH-dehydrogenase). The damage threshold of the diffusing tip was 6 W at 14 min exposure time whereas the Ringmode®-ITT applicator had its limit at 5 W and 12 min exposure. Comparing various exposure times showed that treatment over a time of more than 840 s did not significantly increase the lesion volume. At 5 W and 720 s the mean lesion volume was 6.9±1.1 cm3 with the diffusing tip and 6.3±0.6 cm3 with the Ringmode®-ITT applicator, both having a slight ellipsoidal shape. Hence, the created lesions were not significantly different for both applicators when the same laser parameters were applied. On the other hand, the new diffusing tip had a higher damage threshold and was therefore capable of producing maximal coagulation volumes of up to 7.9±0.5 cm3 at 5 W and 20 min. The experiments showed that lesions with a dimension of 31×22 mm can be achieved with the diffusing applicator which seem suitably sized for treating small human liver metastases in a single laser session.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050018
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Laser Myringotomy (L-Myringotomy) and Ventilating Tubes: A Preliminary Comparative Study (1999)
    Springer
    Lasers in medical science 14 (1999), S. 62-66 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Laser myringotomy; Otitis media with effusion; Tympanic membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. A prospective comparative study was done to assess the validity of laser myringotomy (L-myringotomy) when compared to the insertion of ventilating tubes (VT). In 23 children with chronic otitis media with effusion, a VT was inserted in the left ear while a laser myringotomy was performed in the right ear by using the CO2 Sharplan 1030 laser. After a six month follow-up conducted during the winter months, the results with the laser myringotomy were equal to those in the left ear with the VT. During the follow-up period, three ears required additional laser myringotomy either for early closure or because of otitis media and the accumulation of effusion in the middle ear cavity. Nevertheless, the use of laser has the advantage that there is no foreign body in the ear, the tympanic membrane is closed after four to seven weeks, and since the procedure is very short, the time for anaesthesia is minimal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050022
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Photodynamic Therapy of Malignant Ovarian Tumours Cultivated on CAM (1999)
    Springer
    Lasers in medical science 14 (1999), S. 91-96 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Chorioallantoic membrane (CAM); Liposomes; Methylene blue; Ovarian cancer; Photodynamic therapy; Photosensitiser
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. The disappointing results with either surgery alone and/or chemotherapy in the treatment of malignant ovarian tumours have led to an increased interest in additional treatment schedules. Photodynamic therapy (PDT), a modality involving the use of a photosensitising drug and activating light, is being used increasingly as a local treatment for neoplastic lesions. The synthesis and evaluation of new photosensitisers for the treatment of gynaecological lesions and malignancies continues to be an active area of investigation for proper application of the photodynamic process in the gynaecological field. The effect of PDT using methylene blue (free and combined with liposomes) as a photosensitiser for treating human ovarian malignant tumours cultivated on the chorioallantoic membrane was evaluated. Two days after PDT, the treated implanted tumours were markedly decreased in size. Areas of necrosis with black coloration, dryness and eschar formation were observed. Five days after PDT, tumour remission was clearly observed in all the treated tumours. Photodynamic therapy using methylene blue (aqueous and coupled with liposomes) is effective for treating the ovarian malignancies and it will be capable of achieving complete eradication of visible tumours in patients with superficial lesions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050028
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    The Monitoring of ALA-Induced Protoporphyrin IX Accumulation and Clearance in Patients with Skin Lesions by In Vivo Surface-Detected Fluorescence Spectroscopy (1999)
    Springer
    Lasers in medical science 14 (1999), S. 112-122 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Aminolaevulinic acid; Dermatology; Photodynamic therapy; Photosensitisation; Protoporphyrin IX; Skin lesions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. The method of surface-detected fluorescence has been used to monitor the emission intensity from 5-aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) in lesions and corresponding adjacent normal skin. Three types of lesions were examined: psoriatic plaques, actinic keratosis and basal cell carcinoma. This study included a total of 14 human volunteers on whom ALA-induced PpIX formation and clearance was monitored for a total of 48 h post-ALA application. Both an ALA dose-ranging study, as well as a comparison of results between normal and lesional tissue at a fixed ALA dose, were carried out. For the dose range examined (10–30%), there was no ALA dose dependency of the PpIX fluorescence for any of the lesions tested. Although all three lesions tested did show enhanced PpIX fluorescence as compared with normal skin, there was considerable lesion-to-lesion variability. Thick psoriatic plaques seem to give longer PpIX retention times than those of thin lesions. Limitations of the surface-detected fluorescence methodology are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050032
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Changes in Local Hepatic Blood Perfusion During Interstitial Laser-Induced Thermotherapy of Normal Rat Liver Measured by Interstitial Laser Doppler Flowmetry (1999)
    Springer
    Lasers in medical science 14 (1999), S. 143-149 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Interstitial laser therapy; Liver; Perfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. Interstitial laser Doppler flowmetry was used to measure the effect of interstitial laser-induced thermotherapy on local blood perfusion in normal rat liver in the peripheral treatment region elevated to hyperthermic temperatures. The Nd:YAG laser emitting at 1064 nm was utilised as heat generation source. The plane-cut tip of an optical fibre was placed in the middle of the exteriorised left liver lobe. Blood perfusion and temperature were measured in the liver parenchyma 4 mm from the laser fibre. The temperature at the location of the liver temperature sensor was maintained at 41 or 44°C during 30 min by regulating the power of the heating laser. The laser Doppler signal was recorded during and after heat treatment, for a total time of 60 min. At 41°C, a significant increase in perfusion up to 1.3 times the initial value was observed 2–16 min after start of treatment. At 44°C, perfusion decreased continuously during and after treatment, and was significantly different from control 40 min after start of treatment. The results may be valuable in assessing the thermal response of tissues surrounding the target in interstitial laser-induced thermotherapy of liver tumours during conditions of normal blood flow.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050036
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Picosecond Laser Ablation of Dentine in Endodontics (1999)
    Springer
    Lasers in medical science 14 (1999), S. 168-174 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Endodontics; Laser ablation; Nd:YAG laser; Picosecond laser; Root canal therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract . The interaction of picosecond laser radiation with human dental tissue was investigated in this study, in order to determine the ablation rates and the surface characteristics of the dentine by using scanning electron microscopy (SEM). Dentine ablation was performed by using tooth sections of different thicknesses (0.5–2.0 mm). Dental tissue samples were irradiated in air with the fundamental wavelength and first harmonic of a regenerative amplifier Nd:YAG laser system, at 1064 nm and 532 nm, respectively, with a pulse duration of 100 ps and a pulse repetition rate of 10 Hz. The results showed very clean craters surrounded by minimum melting of the surface of dentine when the 1064 nm pulses were used. In contrast, when the first harmonic 532 nm pulses were used, the SEM examinations revealed cracks and melting of dentine with irregular surface modification. Consequently, it seems that cleaning and shaping of the root canal walls during endodontic therapy with the picosecond Nd:YAG laser application may be possible in the future. The, as yet unexplored, field of the picosecond laser interaction with hard dental tissue is expected to be a potential alternative for powerful laser processing of biomedical structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050080
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Photodynamic Inactivation of the Single Crayfish Nerve Cell: Dynamics of Electrophysiological Responses and Comparison of Photosensitisers (1999)
    Springer
    Lasers in medical science 14 (1999), S. 185-195 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Chlorins; Firing; Janus green B; Methylene blue; Neuron; Photodynamic effect; Photoheme; Photoporphyrin IX; Photosens; Photosensitisers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract . The study of single neuron response to photodynamic effect provides a means for the study of the dynamics of cytotoxic events leading to cell death and allows comparison of the phototoxicity of different photosensitisers. Isolated crayfish stretch receptor neurons were photosensitised for 30 min, then irradiated with a He-Ne laser (632.8 nm; 0.3 W/cm2) until irreversible firing cessation. The dynamics of neuron firing frequency were continuously recorded throughout. The following photosensitisers were studied: methylene blue, janus green B, protoporphyrin IX, chlorins e 6 and p 6, haematoporphyrin derivative (Photoheme) and sulphonated aluminium phthalocyanine (Photosens). Nerve cells were found to be insensitive to either He-Ne laser irradiation or photosensitisation alone, but very vulnerable to the photodynamic effect: neurons changed firing rate and died at nanomolar concentrations of photosensitisers. The dynamics of neuron responses was found to depend on photosensitiser type and concentration. The current approach provides a means of evaluation of initial threshold cell membrane alteration and cytotoxic events leading to cell death. The dependence of firing acceleration rate and neuron lifetime on photosensitiser concentration additionally allowed comparison of efficiencies of different photosensitisers. Photosens, Photoheme and chlorin p 6 were found to be the most potent photosensitisers: neurons responded to their photodynamic effects at concentrations as low as 1–5 nM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050083
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Disinfection of the Optical Fibre of a Nd-YAP Laser Used in Dental Care (1999)
    Springer
    Lasers in medical science 14 (1999), S. 73-80 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Biocides; Disinfection; Laser; Optical fibre
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. In order to set up a disinfection protocol, the tip of the optical fibre of an Nd-YAP laser, λ=1.34 μm, was contaminated in vitro with: Mycobacterium smegmatis (CIP 7326), Candida albicans (ATCC 2091), Bacillus stearothermophilus (ATCC 7953) or Streptococcus sanguis (ATCC 10556). It was then treated with various biocidal solutions, Septinol® V, glutaraldehyde 2%, ethanol 95° and NaOCl 6%, using one of two protocols: 10 s of contact, or 5 s of contact followed by 5 s of wiping. The latter technique proved to be the most effective. Whatever the biocidal solution used, all the bacteria adhering to the fibre were eliminated. The protocol was checked in vivo in the canals of 10 teeth presenting root canal infections. No bacteria withstood the treatment with Septinol® V. This treatment does not alter the qualities and performance of the fibre as far as light transmission is concerned.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050024
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Diode Laser Trabeculoplasty Versus Argon Laser Trabeculoplasty in the Control of Primary Open Angle Glaucoma (1999)
    Springer
    Lasers in medical science 14 (1999), S. 105-108 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Glaucoma, open angle; Intraocular pressure; Laser surgery; Trabecular meshwork; Trabeculoplasty
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. A randomised prospective study was carried out to determine whether diode laser trabeculoplasty (DLT) is as effective as argon laser trabeculoplasty (ALT) in the control of primary open angle glaucoma (POAG). Forty eyes of 40 patients with uncontrolled intraocular pressure (IOP) despite maximum topical medication were entered into the study. Twenty eyes received DLT, spot size 100 μm, exposure time 0.2 s, mean power 1034 (±56.4) mW. Twenty eyes received ALT, spot size 50 μm, exposure time 0.2 s, mean power 528 (±44.7) mW. They were reviewed at 2 h, 2 and 8 weeks, and 3, 6, 12, 18 and 24 months after laser treatment. Two eyes were withdrawn from the DLT group and four from the ALT group because of uncontrolled IOP during follow-up. Of the remaining eyes in the trial, mean IOP reductions for DLT and ALT, respectively, were: 6 months 7.42 (±2.36) mmHg and 6.36 (±2.3) mmHg; 12 months 7.02 (±2.6) mmHg and 6.28 (±2.2) mmHg; 18 months 6.86 (±2.8) mmHg, 5.98 (±2.02) mmHg; 24 months 6.50 (±2.72) mmHg, 5.92 (±2.02) mmHg. There was a significant reduction in each laser group when IOP at each stage was compared with baseline (p〈0.001) (paired Student's t-test), but no significant difference between the two groups. In the ALT group peripheral anterior synechiae developed in four eyes and post laser pain in seven eyes. These complications were not noted following DLT. We conclude that DLT and ALT are equally effective in IOP control, but DLT is associated with less anterior segment inflammation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050030
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Laser-Induced Thermotherapy (LITT) for Retreatment of Locally Advanced Recurrences of Breast Cancer (1999)
    Springer
    Lasers in medical science 14 (1999), S. 136-142 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Colour-coded duplex sonography; Laser induced thermotherapy; Minimal invasive therapy; Recurrent breast cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. The effect of laser-induced thermotherapy (LITT) as a palliative method for treatment of patients with local recurrence of breast cancer is investigated. This report describes the use of interstitial laser photocoagulation to manage such lesions. The interstitial laser applications were performed in seven women with locally recurrent breast carcinoma on the chest wall after mastectomy. All patients had been heavily pretreated with conventional modes of therapy (radiotherapy, chemotherapy, hormonal therapy, surgical resection). A Nd:YAG laser with a wavelength of 1064 nm was used to heat the lesions. Heat expansion was controlled digitally and monitored by ultrasonography and colour-coded duplex sonography (CCDS). In five women this minimally invasive method enabled the precise coagulation of the subcutaneous tumour without destruction of the skin or ulceration, although these areas had been pretreated by irradiation up to 60 Gy. In two patients with extensive multiple metastases and with skin infiltration, secondary skin ulceration and delayed healing was observed. For palliative reasons, LITT under CCDS guide can aid in local control of chest wall recurrence following mastectomy in selected patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050035
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Killing of the Yeast and Hyphal Forms of Candida albicans Using a Light-Activated Antimicrobial Agent (1999)
    Springer
    Lasers in medical science 14 (1999), S. 150-157 
    Details
    ISSN: 1435-604X
    Keywords: Keywords:Candida albicansCandidosis; Hyphae; Lethal photosensitisation; Toluidine blue O; Yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. Oral infections due to Candida albicans are a common occurrence in patients with acquired immunodeficiency syndrome (AIDS). The purpose of this investigation was to determine whether the yeast and hyphal forms of the organism could be killed using the light-activated antimicrobial agent toluidine blue O (TBO). Three variables were investigated: TBO concentration, laser light dose and pre-irradiation time (PIT). Irradiation with light from a helium neon (HeNe) gas laser used in conjunction with the photosensitiser TBO resulted in substantial kills of both the yeast and hyphal forms. Killing was light dose-dependent with 42 J being the most effective dose. The optimum PIT for the yeast form was 5 min, whereas killing of the hyphal form was not affected by PIT. The results of this study have shown that both forms of C. albicans are susceptible to lethal photosensitisation using TBO in conjunction with HeNe laser light, suggesting the possibility that this approach could be useful for eliminating the organism from diseased lesions in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050037
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Interstitial Laser Photocoagulation with Four Cylindrical Diffusing Fibre Tips: Importance of Mutual Fibre Distance (1999)
    Springer
    Lasers in medical science 14 (1999), S. 216-220 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Beamsplitter; Liver; Metastases; Nd:YAG; Tumour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract . Simultaneous application of multiple fibres could increase the volume of coagulation produced with interstitial laser photocoagulation (ILP) for solid tumours. To take full advantage of the presumed synergistic thermal effect between the fibres, the optimal combination of laser power and distance between the fibres was investigated. Four fibres with a cylindrical diffusing tip of 2 cm length were used, coupled to an optical beamsplitter for Nd:YAG light (four channels, maximal variation 9.5%, transmission 〉85%). The distance between the fibres was 1, 1.5, 2, 2.5 , 3 or 4 cm with a power output of either 4, 5, 6 or 7 W/fibre; energy per fibre was constant at 1800 J by adjusting exposure time. After laser application, dimensions of the coagulated lesions were measured. The optimal mutual fibre distance was 2 cm ( p〈0.01) at all power levels. This resulted in lesions with a mean (SD) volume of 44.5 (2.1) cm3 and a largest diameter of 5.1 (0.4) cm at 7 W/fibre. Smaller distances between the fibres resulted in smaller lesions with central carbonisation, whereas larger distances resulted in four separate zones of coagulation. It was concluded that simultaneous application of four interstitial fibres may result in a considerable increase of volume of coagulation. Fibre position and mutual fibre distance determines whether synergism of the coagulative effect occurs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050087
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    New Laser Literature (1999)
    Springer
    Lasers in medical science 14 (1999), S. 244-246 
    Details
    ISSN: 1435-604X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050091
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    A Comparative Optical Analysis of Cylindrical Diffuser Fibres for Laser Therapy Using Fluorescence Imaging (1999)
    Springer
    Lasers in medical science 14 (1999), S. 257-268 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Diffuser; Emission profile; Fluorescence imaging; Interstitial laser photocoagulation; Photodynamic therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract . Cylindrical light diffusers are commercially available for clinical applications such as photodynamic therapy (PDT) and interstitial laser photocoagulation (ILP). A fluorescence imaging technique has been used to quantify the light distribution produced by each of six different diffuser fibres. The light distribution produced by each device was found to depend on the distance the light propagated in the fluorescent dye solution. At a distance of 1 mm from the diffuser midline, the measured profiles were found to be consistent with published results obtained in air at a similar distance. The three devices intended for PDT utilised scattering particles and reflectors in their construction. The profiles produced by these applicators revealed peaks that were attributed to the reflectors located at their distal tips. By comparison, the two etched ILP fibres displayed either a strong modulation in the profile due to non-uniform etching or a predominant forward peak associated with the conical shape of the tip. We conclude that it is important to take into account the forward-directed light emitted by the diffusers when considering clinical applications using these devices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050093
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Long Exposure Growth of In-Vivo Interstitial Laser Photocoagulation Lesions (1999)
    Springer
    Lasers in medical science 14 (1999), S. 297-306 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Bioheat transfer equation; ILP; In vivo; LITT; Photocoagulation; Rate kinetics; Temperature distribution; Thermal lesion size; Thermotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract . An investigation of the temperature response and growth of thermal lesions resulting from in vivo, interstitial laser photocoagulation at long exposures was conducted to assess extended lesion growth characteristics and test the applicability of first order unimolecular rate kinetics (Arrhenius theory) to thermal lesion growth. Irradiations were performed in vivo in rabbit muscle using a continuous 805 nm diode laser source operating at 1.0 W coupled to an optical fibre with a precharred tip (i.e. point heat source). Temperature responses were measured using a linear array of five microthermocouples. Each temperature–time profile was fitted to a solution of the Weinbaum–Jiji bioheat transfer equation (W–J BHTE). Lesions were resected 48 h post-irradiation and the necrosis boundaries were determined histologically. Numerical integration of the Arrhenius damage integral using temperature–time data at the lesion boundary produced corresponding pairs of activation energy and pre-exponential factor (E a, α) consistent with reported values for various other end-points and tissue types. Lesion radii were 6.0±0.6, 8.7±0.4 and 9.7±0.5 mm for 10, 20 and 30 min irradiations respectively. Thermal lesion growth predicted from Arrhenius theory was consistent with experimental results and is non-asymptotic by 30 min. Thermal parameters generally assumed to be constant when solving the W–J BHTE were found to vary with radial distance from the source, presumably due to a temperature dependence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050097
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Laser Therapy in Maintenance of the Patency of Expandable Metal Stents (1999)
    Springer
    Lasers in medical science 14 (1999), S. 20-23 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Diode laser; Expandable metal stent; Malignant dysphagia; Nd-YAG; Overgrowth; Tumour in-growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. Re-establishment of the oesophageal lumen is the main focus of care in patients with dysphagia due to re-blockage of in situ expandable metal stent (EMS). A total of 51 patients aged 44–89 years were intubated with EMS for dysphagia due to inoperable oesophagogastric carcinoma. Of these patients, 25 required follow-up endoscopy at variable intervals after stent insertion; 17 patients were found to have significant tumour in-growth (9), overgrowth (4) or both (4). All these patients were treated with Nd-YAG (70 W/s) or diode laser (30–50 W, continuous) for maintenance of satisfactory swallowing. The intensity of tumour ablation was similar with both types of lasers but four patients being treated with Nd-YAG laser developed deformity of EMS. This complication was not encountered with diode laser. The timing of the stent insertion should be carefully chosen since the longer the stent is in situ, the greater is the likelihood of tumour ingrowth or overgrowth. The combination of endoscopic laser therapy (ELT) and EMS may offer the best palliation, particularly when patient survival of several months is anticipated. ELT can effectively deal with tumour in-growth and overgrowth but care must be exercised in the use of Nd-YAG which can damage the structure of the EMS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050016
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    The Holmium Laser for the Treatment of Benign Prostatic Hyperplasia: A Brief Review (1999)
    Springer
    Lasers in medical science 14 (1999), S. 86-90 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Benign prostatic hyperplasia; Enucleation; Holmium; Laser; Prostatectomy; Resection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. At a wavelength of 2140 nm, the holmium:YAG (Ho:YAG) laser can be used for incision, ablation and resection of prostatic tissue. This laser has revolutionised the surgical management of benign prostatic hyperplasia (BPH) in our institution. Five different techniques have been utilised in evolving the current techniques using the Ho:YAG laser either alone or in combination with neodymium:YAG (Nd:YAG laser for the surgical management of BPH. The clinical outcome of 664 patients undergoing these procedures is presented. Enucleation of the prostatic adenoma using the holmium laser energy is the most common procedure presently performed at our institution for the surgical management of BPH. A mechanical tissue morcellator appears to be the most efficient way to remove prostatic tissue, once enucleated, from within the bladder.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050027
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...