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  • 1
    Electronic Resource
    Electronic Resource
    A novel spin-finishing method for antistatic modification of polyester fiber. Surface reaction onto amine-containing copoly(amide-ethers) blended with polyester fiber (1997)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 246 (1997), S. 109-123 
    Details
    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.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1997.052460109
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  • 2
    Electronic Resource
    Electronic Resource
    Ring-opening polymerization of cyclobutane adduct of dimethyl 1,1-dicyanoethylene-2,2-dicarboxylate and ethyl vinyl ether (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 1563-1570 
    Details
    ISSN: 0887-624X
    Keywords: cyclobutane ; ring-opening polymerization ; alternating copolymer ; dimethyl 1,1-dicyanoethylene-2,2-dicarboxylate ; vinyl ether ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For an extension of the work on the ring-opening polymerizations of cyclobutane adducts of strong donor olefins and strong acceptor olefins yielding novel alternating copolymers of those olefins, the ring-opening polymerization of the cyclobutane adduct 3 of dimethyl 1,1-dicyanoethylene-2,2-dicarboxylate (DDED) and ethyl vinyl ether (EVE) is investigated. Cyclobutane 3 reacted with methanol and acetic acid at ambient temperature to yield the corresponding ring-opened adducts. The polymerizations of 3 were carried out with anionic initiators, tertiary amines, ammonium halides, and Lewis acids, respectively, according to the polymerization methods of the cyclobutane adduct 1 of tetracyanoethylene (TCNE) and EVE. All these polymerization catalysts except for ammonium halides were effective for the polymerization of 3, yielding alternating copolymers of DDED and EVE. The chain transfer reactions of the polymerization with anionic initiators are also discussed on the basis of a model reaction. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1563-1570, 1997
    Additional Material: 5 Tab.
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  • 3
    Electronic Resource
    Electronic Resource
    Surface and morphological characterization of polysiloxane-block-polyimides (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 2239-2251 
    Details
    ISSN: 0887-624X
    Keywords: polysiloxane-block-polyimide ; solution imidization ; surface properties ; surface enrichment of segment ; surface tension ; morphology ; topography ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two series of polysiloxane-block-polyimides were synthesized by the method of solution imidization of the polyamic acids prepared from the dianhydride/diamine combinations of 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride (DSDA)/2,2-bis[4-(4-aminophenoxy) phenyl] propane (BAPP) (Series A) and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA)/bis[4-(3-aminophenoxy) phenyl] sulfone (BAPSM) (Series B) with three kinds of w-diamino-poly(dimethylsiloxane) with different number-average molecular weight added as a part of diamine. These polysiloxane-block-polyimides, having various compositions and chain lengths of the polysiloxane segments, were subjected to solution casting to prepare their films, and their surface and interface properties were analyzed by contact angle, XPS, AFM, and SEM. It was found that the surface tension and surface topography were greatly influenced by the composition and molecular weight of the polysiloxane segments because of their surface enrichment, which was affected by the environment and substrate with which the copolyimides had contacted. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2239-2251, 1997
    Additional Material: 16 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    A facile antistatic modification of polyester fiber based on ion-exchange reaction of sulfonate-modified polyester and various cationic surfactants (1997)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 251 (1997), S. 181-191 
    Details
    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: Eine neue Methode zur antistatischen Ausrüstung von Polyethylenterephthalat-(PET)-Fasern wurde entwickelt. Hierbei werden durch Blend-Spinnen hergestellte Polyesterfasern aus PET und Poly(ethylenterephthalat/5-sulfoisophthalat) während des Ftirbens mit verschiedenen kationischen oberflachenaktiven Substanzen behandelt. Diese oberflachenaktiven Substanzen werden als Gegenionen zu den 5-Sulfoisophthalat-Gruppen auf der Faser immobilisiert und unterstutzen die Freisetzung statischer Elektronen in der Faser. Dadurch sinken die Halbwertszeit (t112) des Ab- baus statischer Aufladung und der Oberfachenwiderstand (Rs) der Blend-Fasern. Die besten Ergebnisse wurden mit einem methylierten quaternaren Ammoniumsalz eines Stearylamin-Ethylenoxid(E0)-Adduktes und dem Hydrochlorid eines Lauryl- amin-EO-Adduktes mit jeweils etwa zehn EO-Einheiten als oberflachenaktiver Sub- stanz erhalten. Auch nach funf Waschzyklen lag die Halbwertszeit t1/2, unter 30 s bei einem Rs-Wert in der Größenordnung von 1013 Ω cm-2. Mit dieser Technik lieBen sich demnach Polyesterfasem mit “semi-permanenten” antistatischen Eigenschaften produzieren, die durch entsprechende Nachbehandlung, auch nach vollstandigem Verlust, wiederhergestellt werden könnten.
    Notes: A new technique for imparting antistatic properties to poly(ethylene terephthalate) (PET) fiber has been developed. In this technique, blend polyester fibers containing poly(ethylene terephthalate/5-sulfoisophthalate) (SIP-PET) were prepared by blend spinning and then treated with various cationic surfactants in the process of dyeing. The surfactants could effectively be immobilized on the fiber as the counter cations of the sulfonate groups of the 5-sulfoisophthalate (SIP) units and aid the release of static electrons formed in the fiber. Thus, the half-life time (t1/2) of leakage of static charge and the surface resistivity (Rs) of the blend PET fibers became much lower after treating. The best result was obtained with a methylated quaternary ammonium salt of a stearylamine-ethylene oxide (EO) adduct or hydrochloride of a laurylamine-EO adduct as the surfactant of which the number of EO units was around ten. Even after five washing cycles the t1/2 value of the fibers treated with these surfactants was kept lower than 30 s with the Rs value maintained in the order of 1013 Ω cm-2. Therefore, the present technique could be useful for practical production of polyester fibers with “semi-permanent” antistatic properties which can be recovered by re-treatment even if they were lost.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1997.052510116
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  • 5
    Electronic Resource
    Electronic Resource
    Luminescence quenching of partially quaternized poly(1-vinylimidazole)-bound ruthenium(II) complex in methanol (1997)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 198 (1997), S. 959-967 
    Details
    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.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1997.021980404
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  • 6
    Electronic Resource
    Electronic Resource
    Isolation and cationic ring-opening polymerization of 2,3,5,6-tetrahydroimidazo[2,1-b][1,3]oxazole to produce a thermally stable polyurea (1997)
    Weinheim : Wiley-Blackwell
    Macromolecular Rapid Communications 18 (1997), S. 897-902 
    Details
    ISSN: 1022-1336
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A bicyclic pseudourea, 2,3,5,6-tetrahydroimidazo[2,1-b][1,3]oxazole (1), was isolated for the first time, and its cationic and spontaneous polymerizations were examined. Both polymerizations gave poly(1,3-imidazolidin-2-one-1,3-diylethylene) (2) in high yields. The polymer is a crystalline solid with glass transition and melting temperature of 51°C and 286°C, respectively. Thermogravimetry showed that it is stable up to 450°C under nitrogen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/marc.1997.030181001
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  • 7
    Electronic Resource
    Electronic Resource
    Copolymerization of γ-butyrolactone and β-butyrolactone (1997)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 198 (1997), S. 1109-1120 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The copolymerization of a 4-membered β-butyrolactone (βBL) and a thermodynamically stable 5-membered γ-butyrolactone (γBL) proceeds in the bulk state with BF3 · OEt2 as a catalyst at room temperature to give poly[(3-hydroxybutyrate)-co-(4-hydroxybutyrate)] (P(3HB-co-4HB)) whose structure is identical with that of a polyester formed by microorganisms. The copolymer structure was confirmed by 1H and 13C NMR spectroscopy. The monomer reactivity ratios were r(γBL) = 0.48 and r(βBL) = 0.58, respectively, and the unit composition of 4HB increases to 56% at high γBL to βBL ratio in the feed. End group analysis of the copolymer suggests the presence of a hydroxyl group and a carboxyl group at the ends of each polymer molecule. It was postulated that the monomers activated by BF3 react with the hydroxy group derived from the water contaminant in the monomers.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1997.021980414
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  • 8
    Electronic Resource
    Electronic Resource
    Excellent gelators for organic fluids: Simple bolaform amides derived from amino acidsThis work was supported by Grant-in-Aid for Scientific Research on Priority Areas, “New Polymers and Their Nano-Organized Systems” (No. 277/08246101) and a grant (No. 09450347) from the Ministry of Education, Science, Sports and Culture. (1997)
    Weinheim : Wiley-Blackwell
    Advanced Materials 9 (1997), S. 1095-1097 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/adma.19970091405
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  • 9
    Electronic Resource
    Electronic Resource
    Chemo-, Regio-, and Stereoselective Diels-Alder Reaction of Ambident Dienophilic Monothiomaleimide (1997)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 907-923 
    Details
    ISSN: 0947-3440
    Keywords: Cycloadditions ; C=S Dienophile ; N-Arylmonothiomaleimides ; Chemo-, regio-, and stereoselectivity ; AM1 calculation ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Both the C=S and C=C functionalities of N-arylmonothiomaleimides readily undergo a [4 + 2] cycloaddition reaction at ambient temperatures with both electron-donating and -withdrawing dienes. The C=S groups of N-arylmonothiomaleimides are generally more reactive than the C=C groups, especially toward dienes bearing conjugation and electron-attracting groups, and provide mixtures of ortho,endo products 3 and ortho,exo products 4 with complete regioselectivity (100% ortho) and with high stereoselectivity (more than 86% endo). The C=C groups, on the other hand, display a high stereoselectivity (100% endo) but a low regioselectivity, providing ortho,endo adducts 5 and meta,endo adducts 6 in ratios ranging from 1:1 to 6:1. Compared with N-phenylmonothiomaleimide (1). N-p-nitrophenylmonothiomaleimide (11a) is more reactive and displays a higher C=S vs. C=C chemoselectivity in favor of C=S, while N-p-anisyl (11b) and N-benzyl (11c) derivatives display quite the reverse reactivity and selectivity. N-Phenylmonothiocitraconimide (11d) serves as a C=S specific dienophile and reacts with dienes to furnish ortho,endo adducts 12 with excellent regio- and stereoselectivities (100% ortho,endo). Both hard (BF3 · OEt2, TiCl4) and soft (CuBr · SMe2) Lewis acids enhance the reaction rate enormously and increase chemoselectivity in favor of C=S. The chemo- (C=S/C=C), regio- (ortho/meta) and stereochemical outcomes (endo/exo) are rationalized by transition structure analysis based on AM1 calculation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199719970520
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  • 10
    Electronic Resource
    Electronic Resource
    Lipid-induced Secondary Structures and Orientations of [Leu5]-enkephalin: Helical and Crystallographic Double-bend Conformers Revealed by IRATR and Molecular Modelling (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Peptide Science 3 (1997), S. 65-81 
    Details
    ISSN: 1075-2617
    Keywords: [Leu5]-enkephalin ; secondary structure ; IRATR ; MMX force field ; bioactive conformation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Lipid-induced secondary structures and orientations of the two enantiomeric [Leu5]-enkephalins, L-Tyr-Gly-Gly- L-Phe-L-Leu, and D-Tyr-Gly-Gly-D-Phe- D-Leu, on flat multi-bilayers of 1-palmitoyl-2-oleoyl-sn- glycero-3-phosphocholine (POPC) were examined with polarized attenuated total reflection IR (IRATR) spectroscopy and molecular mechanics procedures. The membrane-bound peptides showed identical IR spectra in the amide I and II band regions that indicated membrane-induced secondary structures and specific orientations of the non-zwitterionic molecules. A Lorentzian band shape analysis based on second derivatives of the original curves and the observed band polarizations suggested the presence of helical structures (βIII-and α-turns), oriented more or less perpendicular to the membrane surface. Other folded structures, e.g. βI- and γ turns, were not excluded. Molecular modelling of non-zwitterionic [Leu5]-enkephalin with two βIII-turns or an α-turn resulted in essentially four low-energy conformers containing (i) two βIII-turns, (ii) one α-turn, (iii) a βIII-turn fused to an α-turn, and (iv) a βIII-turn fused to a βI-turn as in the crystallographic molecular conformation described by Aubry et al. [Biopolymers 28, 27-40 (1989)]. Zwitterionic [Leu5]-enkephalin with two β III-turns collapsed to a C13 turn (a distorted α- turn) bridged by a γI-turn (v). The alignment of the amide I oscillators within the helical structures, (i), (ii) and (iii), and the double-bend structures, (iv) and (v), explained the observed amide I and II polarizations. Differences between these and other lipid-induced [Leu5]-enkephalin conformers reported in the literature may be caused by the lipid polymorphism of the model membranes used. Possible implications of the new conformers for the molecular mechanism of opioid receptor selection are discussed in terms of the membrane compartments theory. © 1997 European Peptide Society and John Wiley & Sons, Ltd.
    Additional Material: 9 Ill.
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