摘要:

AbstractThe shrinkage of copolyesters from terephthalic acid, isophthalic acid, and butanediol during injection molding and the after‐shrinkage during annealing exhibits a minimum at 20 mole‐% isophthalic acid. Polyesters of this composition have proved to be new outstanding materials for secondary coating of quartz glass optical fibres. They allow the production of optical fibre constructions without any increase in optical damping down to −

ISSN:0323-7648    

DOI:10.1002/actp.1990.010410901

出版商:Akademie Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractThe photostability of a coil‐coating composite consisting of layers of plasticized PVC and a methylmethacrylate/ethylacrylate/acrylic acid copolymer as well as of several model systems was investigated. Changes of the UV irradiated samples were characterized by UV‐vis spectroscopy, the determination of the remaining thermal stability of PVC, and checking the adhesion strength. Photooxidation may cause failure of the coating especially by degradation in the interface layer of the primer to the me

ISSN:0323-7648    

DOI:10.1002/actp.1990.010410902

出版商:Akademie Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractMolecular weight distributions of poly(dimethyl diallyl ammonium chloride) were determined from sedimentation velocity measurements. After a presentation of the experimental basis for the evaluation of distribution curves, molecular weight distribution curves for different samples were discussed and compared with results of solution fractionations and kinetic‐mechanistic investigation

ISSN:0323-7648    

DOI:10.1002/actp.1990.010410903

出版商:Akademie Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractBy aminolysis of poly(acrylonitrile) with dicyandiamide and a subsequent reaction with hydroxylamine, polyampholytes are formed, which exhibit different ranges of insolubility around the isoelectric point. The reason for the improved solubility of the twice modified polymer is its higher concentration of dissociable functional groups. The aggregation behaviour of the polyampholyte is discussed on base of the intrinsic viscosities measured in dependence on thepH value.

ISSN:0323-7648    

DOI:10.1002/actp.1990.010410904

出版商:Akademie Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractPolymermischungen aus Poly(phenylenbenzimidazolterephthalamid) und Poly(anilinfluorenterephthalamid) wurden durch Synthese eines Polyamids in der Matrix des anderen hergestellt. Der Einfluß des Matrix‐Polymers auf das Kriech‐, Deformations‐ und Festigkeitsverhalten von Folien aus den Polymermischungen wurde unte

ISSN:0323-7648    

DOI:10.1002/actp.1990.010410905

出版商:Akademie Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractSynthese und Eigenschaften einiger Poly(methacryloyloxyalkylenoxybenzoesäure‐4′‐subst.‐anilide) werden beschrieben. Das Ziel der Synthese, Polymere mit flüssigkristallinen Eigenschaften zu erhalten, wird insbesondere durch Copolymerisation mit anderen Methacrylaten

ISSN:0323-7648    

DOI:10.1002/actp.1990.010410906

出版商:Akademie Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractAnhand von Modellrechnungen wird gezeigt, wie sich athermische und thermische Keimbildung auf den zeitlichen Verlauf der Hauptkristallisation von Polymeren auswirken, wenn unterschiedliche Sphärolithmodelle zugrunde gelegt werden. Die Überlegungen machen deutlich, daß die aus Meßkurven α(t)zu ermittelnden Parameter Keimdichte, Sphärolithform und radiale Wachstumsgeschwindigkeit komplex über die Kristallisationszeit miteinander verknüpft sind. Eindeutige Aussagen über diese Größen sind deshalb nur in Sonderfällen oder durch Einbeziehung weiterer Informationen über die Kristallisationskin

ISSN:0323-7648    

DOI:10.1002/actp.1990.010410907

出版商:Akademie Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractThe influence of blasting speed of cooling air on the structural parameters and physical properties of polypropylene fibres spun with take‐up speeds of 1000 to 5000 m/min is investigated and discusse

ISSN:0323-7648    

DOI:10.1002/actp.1990.010410908

出版商:Akademie Verlag GmbH    

年代:1990

数据来源: WILEY

摘要:

AbstractThe polyesterification of 1,3‐di(carboxymethoxy)benzene with tetraethylene glycol in both equimolar and nonequimolar ratios has been studied over the range of 120 to 160°C in the absence and in the presence of p‐toluenesulphonic acid as catalyst. The experimental results for uncatalyzed reactions agreed quite well with the kinetic equations proposed by Flory. The kinetic equations for acid catalyzed reactions, however, are in agreement with the kinetic equation proposed by Lin and Hsieh. The rate constants and activation energies for the uncatalyzed and acid catalyzed reactions were calcul

ISSN:0323-7648    

DOI:10.1002/actp.1990.010410909

出版商:Akademie Verlag GmbH    

年代:1990

数据来源: WILEY

ISSN:0323-7648    

DOI:10.1002/actp.1990.010410910

出版商:Akademie Verlag GmbH    

年代:1990

数据来源: WILEY