ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
  • Wiley-Blackwell  (42)
  • Springer Nature  (16)
  • 1990-1994  (21)
  • 1975-1979  (13)
  • 1965-1969  (10)
  • 1960-1964  (14)
Collection
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 207 (1993), S. 9-21 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wird ein phänomenologisches Modell vorgestellt, mit dem sich das Entstehen starker Anisotropien der physikalischen Eigenschaften semikristalliner Polymerer nach einachsigem Verstrecken beschreiben 1äßt. Dieses Modell führt die Temperatur als expliziten Parameter in die Orientierungsfunktion ein. Es enthält zwei frei wählbare Parameter, die für jedes Polymere durch Anpassen der experimentellen Daten der Doppelbrechung als Funktion des Verstreckverhältnisses bei einer bestimmten Temperatur ermittelt werden konnen. Die berechneten Werte für Elastizitätsmodul, thermische Leitfähigkeit und Expansibilität parallel und senkrecht zur Streckrichtung stimmen in einem wäiten Bereich des Verstreckverhältnisses und der Temperatur mit den experimentellen Ergebnissen gut überein.
    Notes: A phenomenological model has been proposed to understand the development of strong anisotropy in physical properties of semicrystalline polymers on uniaxial drawing. The proposed model introduces temperature as an explicit parameter in the orientation function. The model contains two free parameters for each polymer which can be evaluated by fitting the experimental data on birefringence versus draw ratio at a particular temperature. The calculated values of elastic moduli, thermal conductivity and expansibility along and perpendicular to the drawing direction over the entire range of draw ratio and a wide range of temperature are in good agreement with experimental values.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 179 (1978), S. 1209-1217 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Studies on the relative efficiencies of 3d-transition metal oxides as catalysts for the polymerization of vinyl ethers revealed that V2O5 is the most efficient catalyst. Some kinetic studies with the system isobutyl vinyl ether/V2O5/benzene were carried out at ambient temperature. It was found that the rate is second order in isobutyl vinyl ether (IBVE) concentration (0,25 to 2,0mol.1-1) and the inhibition of the polymerization by pyridine suggests a cationic mechanism. Rp increases by the use of benzaldehyde along with V2O5, whereas water (3.10-3mol.1-1) seems to have no effect on Rp. Over the temperature range of 15 to 60°C, Rp as well as [η] attain a maximum value at about 32°C. [η] is unaffected by varying the amounts of oxides, whereas it increases with increasing IBVE concentration. No stereoregularity in the product polymer was observed by using V2O5 alone or in combination with modifiers such as benzaldehyde or carbon disulfide. The kinetics are interpreted in terms of the Hinshelwood-Langmuire mechanism assuming a single point adsorption.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 7 (1963), S. 2199-2209 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The kinetics of low-temperature (60-100°C.) thermal degradation of deproteinized and deresinified petroleum ether soluble fraction of natural rubber in two chemically inert solvents, cyclohexane and trans-decalin, have been studied. The changes in Mw, A2, and (r2)1/2 at various stages of degradation have been obtained from the lightscattering data. The rate constants and the energy of activation for chain scission have been calculated from the observed variation in Mu. The scission has been found to be random and the average energy of activation is 25.8 kcal./mole. This low-energy requirement suggests the presence of weak links in the rubber molecule which get ruptured at low temperature.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 28 (1990), S. 3795-3800 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 35 (1990), S. 244-251 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Enhancement of the productivity of xylanase and β-xy-losidase of Aspergillus ochraceus was investigated by multistep mutagenesis. The spores of the wild strain were subjected to UV and N-methyl-N-nitro-N-nitro-soguanidine (NTG). The hyperxylanolytic mutant (NG-13), which showed good clearing on the surface of the xylan-agar plate, secretes xylanase and β-xylosidase at high levels during growth on commercial xylan and on agricultural wastes. Both liquid and solid state cultures were employed in the study for enzyme production. The xylanase from NG-13 was purified to homogeneity by ammonium sulfate precipitation and gel filtration. This purified enzyme showed a pH optimum of 6.0 and was stable in the range of pH 5 to 10. Prolonged stability of the enzyme was observed at 45°C though its activity was maximal at 50°C. The molecular weight of the enzyme was estimated to be 4.3 × 104 by SDS-polyacrylamide gel electrophoresis and 5 × 104 by gel filtration on Sephadex G-75. The kinetic data showed that the Km and Vmax values for xylan were 1 × 10-3M and 19.6 μmol/ min/mg protein, respectively. The enzyme was both more active and thermostable in the presence of K+and was inactivated by thiol reagents such as Hg2+, p-hydroxymercuribenzoate (PHMB), 3′, 5′-dithiobis (2′-nitrobenzoic acid) (DTNB), and N-ethylmaleimide (NEM).
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 21 (1963), S. 147-148 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The coulometric determination of tripositive arsenic and antimony by electrogenerated iodine in a NaHCO3 buffered solution of pH 8 has been described. The end point can be determined visually using starch as an indicator. Quantities of As(III) and Sb(III) down to the microgram level can be determined within permissible limits of error.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 737-747 
    ISSN: 0887-6266
    Keywords: Crystallization ; melting ; morphology ; thermoplastic polyimide ; New-TPI ; PMDA ; 33BAPB ; polarizability ; SAXS ; lamellar thickness ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Crystallization, melting, and morphology of a thermoplastic polyimide (New-TPI) containing pyromellitic dianhydride (PMDA) and 3,3'-bis(4-aminophenoxy) biphenyl diamine (33BAPB) moieties have been studied. This material showed a glass transition temperature (Tg) of 250°C, an equilibrium melting temperature (T°m) of 406°C and a heat of fusion (ΔH) for 100% crystallinity of 6.38 kJ/mol. Measurements of the crystallization bulk rate (by DSC) and spherulite growth rate (by optical microscopy) indicated that the maximum crystallization temperature was about 320°C and the crystallization growth process was three-dimensional under thermal nucleation (the Avrami exponent n ca. 4). The rate of nucleation density was estimated to decrease with increasing temperature, and the product of two crystal surface free energies σeσo was calculated to be 1176 erg2/cm4. The meltgrown spherulite consistently showed a Maltese cross pattern with negative birefringence under cross-polars. The calculation of polarizability along the three unit cell axes suggested that the crystal b axis may be along the spherulite growth (radial) direction. Two scattering maxima were seen in small-angle x-ray scattering (SAXS) profiles. The dominant peak indicated a long period of ca. 20 nm which varied as a function of crystallization temperature. The weak peak at a d-spacing of 2.5 nm was independent of temperature and has been attributed to the chemical repeat distance determined by Okuyama et al. (indexed as 001). The lamellar thickness lc, estimated by the correlation function analysis of the SAXS data, was found to be similar to that determined by the Scherrer analysis of the 001 reflection peak. © 1994 John Wiley & Sons, Inc.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A convenient method of preparing zinc ethylenediamine complex (ZED) solution for use as solvent for cellulose pulp is described, and the advantages in using this solvent (0.25M zinc in 41% ethylenediamine in water) over cupriethylenediamine (CED) or cuprammonium solutions for viscometric determination of molecular weight of cellulose are indicated. Intrinsic viscosities of eight rayon-grade pulp solutions have been determined at four temperatures: 15, 20, 25, and 30°C. The constants K = 5.85 × 10-5 and a = 0.936 of the Mark-Houwink equation [η] = KMna, required for evaluating the molecular weight of cellulose pulps in ZED solution, have been determined by using the molecular weight values obtained from CED solutions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 72 (1978), S. 57-66 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Poly(N-vinylcarbazol) wurde mit verschiedenen Reagenzien sulfoniert und die Ionenaustauschkapazität der erhaltenen Harze bestimmt. Eine maximale Kapazität von 4,5 meq · g-1 des trockenen Harzes wurde durch 10stündige Reaktion mit 98,8proz. H2SO4 bei 30°C erhalten. Die pH-Titrationskurven lassen einen starken monofunktionellen Kationenaustauscher mit einem pK-Wert von 2,2 erkennen. Das Harz zeigt eine mäßige Austauschgeschwindigkeit mit NaCl und ist bis zu 250°C thermisch stabil.
    Notes: Poly(N-vinyl carbazole) was sulfonated with different sulfonating agents and ion exchange capacities of the resins produced were evaluated. A maximum capacity of 4.5 meq · g-1 of dry resin was realized when sulfonation was done with 98.8% H2SO4 at 30°C for 10 h. The pH titration curves reveal the nature of a strong monofunctional cation exchanger with a pK value of 2.2. The resin exhibits a moderate rate of exchange with NaCl and is thermally stable up to ca. 250°C.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 73 (1978), S. 53-61 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Ein Kationenaustauscher wurde durch Kondensation von Polyisobutylvinyläther und Furfural hergestellt. Als Katalysator diente konzentrierte Schwefelsäure. Der Austauscher wurde durch Messen der Austauschkapazität, durch Untersuchen seiner thermischen Belastbarkeit und durch Bestimmen seines Verhaltens bei der pH-Titration charakterisiert. Es scheint sich um einen Austauscher mit schwachen Säregruppen zu handlen, die wohl als —COOH-Gruppen vorliegen und durch Oxidation aus den Furfuralgruppen entstanden sein dürften.
    Notes: A cation exchange resin was synthesized from the condensation product of poly(iso-butyl vinyl ether) and furfural by treating it with concentration sulphuric acid. The resin produced was characterized by measuring its total and salt splitting capacities, and by studying its thermal characteristics and behaviour to pH metric titration. The latter suggests the resin to be a weak one possibly containing —COOH groups, which result from the oxidation of the furfural aldehyde group by sulphuric acid.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...