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  • Polymer and Materials Science  (71)
  • 1995-1999  (40)
  • 1980-1984  (31)
  • 1920-1924
  • 1
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 2741-2747 
    ISSN: 0887-6266
    Keywords: FTIR spectroscopy ; poly(ethylene-2,6-naphthalate) ; crystallization process ; induction period ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In situ Fourier transform infrared (FTIR) measurements were carried out to elucidate conformation changes occurring during the isothermal melt crystallization of poly(ethylene-2,6-naphthalate) (PEN). Based on the band assignments for the components of the amorphous, α-crystal form, and β-crystal form of PEN in film samples, the in situ data was analyzed in terms of the amorphous- and crystal-trans conformations. It was observed at a higher isothermal crystallization temperature that the formation of amorphous-trans conformations precedes the growth of crystals. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2741-2747, 1997
    Additional Material: 7 Ill.
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  • 2
    ISSN: 0935-9648
    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
    Additional Material: 2 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 224 (1995), S. 153-166 
    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: Durch Reaktion von Addukten aus Oxiran und Stearylamin mit Natriumchlormethansulfonat wurden neuartige Polyethylenoxidderivate (S-Betain) hergestellt, die hinsichtlich ihrer Eignung als antistatische Modifikatoren für Polyethylenterephthalat(PET)- und Polyamid-6(PA6)-Fasern geprüft wurden. Die Halbwertszeit des Abbaus der elektrostatischen Ladung und der Oberflächenwiderstand von PET- und PA6-Fasern mit 2,0 Gew.-% S-Betain sind geringer als die der unmodifizierten Fasern. Wiederholtes Waschen verringert jedoch die antistatischen Eigenschaften, da der Modifikator ausgewaschen wird. Um dies zu verhindern, wurden copolymerartige Modifikatoren mit sowohl S-Betain- als auch Polyethylenglykol-Strukturen hergestellt und in die Fasern eingearbeitet. Damit bleiben die antistatischen Eigenschaften der PET-Fasern auch nach Färben und wiederholtem Waschen erhalten.
    Notes: New poly(oxyethylene) derivatives (S-betaine) having a zwitterionic structure of ammoniumsulfonate were prepared by the reaction of oxirane (EO) adducts of stearylamine with sodium chloromethanesulfonate and examined as blending antistatic modifiers for poly(ethylene terephthalate) (PET) and polyamide 6 (PA6) fibers. The blend PET and PA6 fibers containing 2.0 wt.-% of S-betaine exhibited a decreased half-life time of leakage of electrostatic charge (t1/2) and a surface area resistivity (Rs) compared with those of the control PET and PA6 fibers. However, their antistatic properties were almost lost after repeated washings, because of the extraction of the agents. To increase the resistivity to washing, copolyester-type modifiers comprising both S-betaine and poly(ethylene glycol) were synthesized and incorporated into PET fibers. It was found that the antistatic properties of the blend PET fibers obtained can be retained even after dyeing and repeated washings.
    Additional Material: 1 Ill.
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  • 4
    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: Blockcopoly(ester-ether) mit verschiedenen ionischen Einheiten wie Sulfobetain (S-Betain), Carbobetain (C-Betain) und Ammoniumtosylat wurden hergestellt und hinsichtlich ihrer Eignung als antistatische Modifikatoren für Polyethylenterephthalat (PET)-Fasern untersucht. Die ionischen Segmente wurden aus N,N-Bis(2-hydroxyethyl)methylamin generiert und statistisch mit den Polyester- und Polyoxyethylen(PEO)-Einheiten cokondensiert. Aus den Copolymeren mit S-Betain-Einheiten wurden im Schmelzspinnverfahren dicke Filamente hergestellt und deren elektrischer Widerstand bestimmt. Abhängig von der Zusammensetzung (25-75 Gew.-% PEO, 1-2 mol-% S-Betain) wurden Widerstände zwischen 108 und 1010 Ω cm-1 gemessen. Die drei copolymerartigen Modifikatoren wurden mit PET durch Blendspinnen gemischt. Die so erhaltenen PET-Fasem zeigen nicht nur gute mechanische sondern auch verbesserte antistatische Eigenschaften. Die Fasern aus dem S-Betain enthaltenden Copolymeren weisen dabei die kürzeste Halbwertszeit des Abbaus der elektrostatischen Ladung auf, obwohl der Oberflächenwiderstand dieses Materials in der Größenordnung 1013 Ω cm-2 dem Wert der mit C-Betain und Ammoniumtosylat hergestellten Fasem ähnlich ist. Die PET-Fasern bewahren ihre guten antistatischen Eigenschften auch nach dem Fäben und wiederholtem Waschen, da sowohl die hydrophilen als auch die ionischen Gruppen an den Polyesterketten fixiert sind.
    Notes: Block copoly(ester-ether)s containing different ionic units, i.e., sulfobetaine (S-betaine), carbobetaine (C-betaine), and ammonium tosylate, were prepared and evaluated as antistatic modifiers of PET fiber. The ionic units were readily derived from N,N-bis(2-hydroxyethyl)methylamine and co-condensed randomly with the polyester and poly(oxyethylene) (PEO) units. For the copolymers containing S-betaine units, a thick filament was melt-spun to evaluate their apparent electric resistivity. Depending on the unit compositions (25-75 wt.-% of PEO and 1-2 mol-% of S-betaine), resistivities ranging from 108 to 1010 Ω cm-1 were obtained. Then, the three copolymer-type modifiers were blended with poly(ethylene terephthalate) (PET) by the ordinary blend-spinning technique. The blend PET fibers obtained showed not only good mechanical properties, but also improved antistatic properties. Particularly, the fiber blended with the copolymer containing S-betaine units had the shortest half-life time of leakage of static charge, although the surface area resistivity, being in the order of 1013 Ω cm-2, was similar to that of the fibers blended with the copolymers containing C-betaine and ammonium tosylate units. These blend PET fibers were found to retain good antistatic properties even after dyeing and repeated washings, because both the hydrophilic and ionic groups are immobilized with the polyester chains.
    Additional Material: 3 Tab.
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  • 5
    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: Copoly (amid-ether) rnit zwei unteschiedlichen Aminfunktionalitäten wurden als antistatische Modifikatoren für Polyethylenterephthalatfasern (PET) eingesetzt. Die tertiären Aminogruppen schmelzegesponnener Copolymerfilamente wurden rnit drei Alkylierungsmitteln umgesetzt, wobei ein Sulfobetain, ein Carbobetain bzw. Ammoniumionen gebildet wurden. Dadurch wurde der scheinbare spezifische Widerstand der Filamente auf größfienordnungsmäßfiig 106 bis 108 Ω/cm verringert. Da sich die quaternisierten Copolymeren beim Blend-Spinnen rnit PET zersetzen, wurden Blendfasern von PET mit einem Copolymeren nach dem Schmelzespinnen einer Quaternisierung oder Vernetzung rnit Alkylierungsmitteln bzw. Epoxyvernetzern unterzogen, was die antistatischen Eigenschaften der Fasern im Vergleich rnit der unbehandelten Faser verbesserte. Insbesondere die mit Epoxiden vernetzten Fasern wiesen antistatische Eigenschaften auf, wie sie mit dieser Modifizierungsmethode bislang nicht erreicht wurden. Die antistatischen Eigenschaften blieben nach dem Fkben erhalten, da sowohl die hydrophilen als auch die ionischen Gruppen auf der Faseroberflache immobilisiert waren. Da Quaternisierung bzw. Vernetzung in einem Arbeitsgang rnit dem Verspinnen und Verstrecken der Fasern innerhalb einer kurzen Reaktionszeit erfolgen, sollte diese “spin-finishing„ genannte Methode konventio- nellen Verfahren bezuglich Kosten und Produktivitat uberlegen sein.
    Notes: Copoly(amide-ethers) containing two types of tertiary amine units were made as antistatic modifiers for poly(ethylene terephthalate) (PET) fibers. The filaments of the copolymers were melt-spun and reacted with three alkylating agents in order to quaternize the tertiary amine into a sulfo-betaine, a carbobetaine, and an ammonium ion. The apparent electric resistivity of the filaments was greatly reduced by this reaction, being in the range of 106 to 108 Ω/cm. However, because these quaternized copolymers incurred decomposition during blend spinning with PET, a blend PET fiber containing one type of copoly(amide-ether) was melt-spun and subjected to quaternization of the amino groups as well as to surface crosslinking with various alkylating and epoxy agents. The quaternized blend fibers obtained showed improved antistatic properties compared with the original blend fiber. Particularly, the fibers crosslinked with epoxy compounds were found to have the best antistatic properties that had ever been attained with this type of modification. The antistatic properties were retained even after dyeing, because both hydrophilic and ionic groups had been effectively immobilized on the surface. Since this quaternization and crosslinking could be conducted on-line with spinning and drawing within a short reaction time, this modification technique is called “spin-finishing method”, which should be superior to the conventional methods in terms of cost performance and productivity.
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  • 6
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 36 (1998), S. 1227-1233 
    ISSN: 0887-6266
    Keywords: FTIR spectroscopy ; isotactic polystyrene ; crystallization process ; induction period ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The melt crystallization process of isotactic polystyrene (i-PS) was studied by means of in situ Fourier transform infrared (FTIR) spectroscopy, with a focus on the conformational changes during the induction period. The spectra obtained during the induction period suggested the occurrence of some ordered structure that is characterized by higher regularity and packing of the helical moieties than observed in the melt. This ordered structure was clearly different from the amorphous structure, and close to the crystal structure. The Avrami analysis indicated that the formation process of the ordered structure at the late stage of the induction period is similar to the growth process of the crystallites after the induction period. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1227-1233, 1998
    Additional Material: 10 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Macromolecular Theory and Simulations 4 (1995), S. 1039-1054 
    ISSN: 1022-1344
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The structure of the repeating units of poly(parabanic acid) (PPA), a polyimide-like glassy heat resistant polymer, was analyzed by MM2 using various model compounds of PPA-M and PPA-T consisting of M (1,3-diazolidine-2,4,5-trione-1,3-diyl-1,4-phenylenemethylene-1,4-phenylene) and T (1,3-diazolidine-2,4,5-trione-1,3-diyl-3,3′-dimethyl-4,4′-biphenylylene) units, respectively. Based on the most stable structures obtained, the subunit rotations of the methylene, phenylene, and diazolidine groups were evaluated. The potential mobilities estimated for these subunits can reasonably be correlated with the dynamic mechanical and dielectric properties of PPA. The γ relaxation mode of both PPA-M and a copolymer PPA-TM is reasonably explained by the rotation of the methylene group. The major mode of the β relaxations of both PPAs is ascribed to the rotation of the phenylene ring of the M unit, while the β* dielectric relaxation is attributed to the torsional vibration of the parabanic ring involving the adjacent aromatic moieties. These data suggest that PPA is similar to polycarbonate rather than polyimide in terms of the local chain motion. It is shown that the conformational analysis by MM2 is quite informative to understand the structure property relationships of polymers.
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  • 8
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Metallopolymers in which bis(2,2′-bipyridine)ruthenium(II) complexes are coordinated to imidazolyl residues on partially quaternized poly(1-vinylimidazole) having different degree of quaternization (RuQPIm) were synthesized. The luminescence quenching of the photoexcited RuQPIms with various alkylviologens having different length of alkyl group was investigated in MeOH. In quenching of RuQPIm with methylviologen (MV2+), the efficiency of quenching decreases with increasing degree of quaternization. This was attributed to the electrostatic repulsion between the MV2+ species and the quaternized imidazolium residue on the polymer backbone and steric hindrance of the alkyl side chain. Furthermore, the efficiency of quenching depends on the length of the alkyl group in viologen. These results suggest that the alkyl side chain on the polymer backbone exerts steric hindrance at low degree of quaternization and van der waals interaction at high degree of quaternization.
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  • 9
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The acetonitrile effects on the quenching and photosensitized charge separation using two partially quaternized poly(1-vinylimidazole)-bound ruthenium(II) complexes, RuQPIm-19 and RuQPIm-44, wherein the numbers represent the degree of quaternization in molar percentage, have been investigated. The systems consist of RuQPIm-19 and RuQPIm-44 as photosensitizers, 1,1′-dimethyl-4,4′-bipyridinium (MV2+) and 1,1′-didodecyl-4,4′-bipyridinium (C12V2+) dications as electron acceptors (quenchers), and triethanolamine (TEOA) as a sacrificial electron donor. The photosensitized charge separation reaction proceeds through two processes, an interactive process and a direct process, i.e., the viologen is undergoing an interaction with these polymers and no interaction, respectively. The charge separation through the interactive process is less effective than that through the direct process, because the reaction through the interactive process is effective for both the forward and the back reactions. With the addition of acetonitrile, the rates of viologen radical formation decrease for RuQPIm-19 and RuQPIm-44, while the quenching efficiency decreases for RuQPIm-19 and increases for RuQPIm-44. In MV2+, the acetonitrile effect contributes to the interactive and direct processes for RuQPIm-19, while it contributes to only the direct process for RuQPIm-44, particularly the forward reaction for RuQPIm-19 and the back reaction for RuQPIm-44. In C12V2+, the interactive process through which the C12V2+ increases, leading to a decrease in the rates for viologen radical formation. Furthermore, these results indicate that the conformational changes in these polymers play an important role in the charge separation reactions.
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  • 10
    Electronic Resource
    Electronic Resource
    Basel : Wiley-Blackwell
    Die Makromolekulare Chemie, Rapid Communications 5 (1984), S. 301-303 
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
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