摘要:

AbstractInfrared spectra of uniaxially drawn ß‐PVDF films under the influence of an electric field were registered. The direction and the strength of the applied field were changed in up to 13 cycles. The field‐induced frequency changes of the bands at 445 cm−1(CF2‐rocking) and 510 cm−1(CF2‐bending) were studied in detail. Model calculations concerning the influence of the field on band frequencies are presented revealing the possibility to discriminate by IR spectroscopy between opposite dipole directions. The experimental results suggest the formation of a remanent field in the samples d

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430101

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractTwo types of main chain mesogenic polyesters were studied by means of polarization microscopy. The morphology of supermolecular structures of as‐obtained polyesters is established. The mesophase textures of the polyesters remain when these are cooled to room temperature. When the polyesters are solved in an appropriate solvent with high concentration, they form optical anisotropic phases. An assumption has been made about the structure organization of crystal phases and of mesomorphous domains at elevated temperature and in solid state after coolin

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430102

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractPolymer dispersed liquid crystal films were prepared from radiation cured polyester resin containing low concentration of the nematic liquid crystal hexyloxycyanobiphenyl. The electro‐optic properties of the liquid crystal domains in the polymer matrix are dependent on the time elapsed between the occurrence of phase separation of the liquid crystal from the homogeneous mixture with the polymer precursor and the onset of polymer hardenin

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430103

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractMorphology evolution in ternary polymer solutions consisting of poly(methyl methacrylate), poly(styrene‐co‐acrylonitrile) having different AN‐contents and toluene was studied by optical microscopy and light scattering. The solutions subjected to different isothermal demixing conditions displayed regularly or irregularly phase separated structures. Effects of the AN‐content of the SAN, the blending ratio and the annealing conditions on the arising morphologies are presented. A criterion for conservation of the periodic bicontinuous structure developed in the unmixing process can be esta

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430104

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe surface tension of molten LDPE can be determined with the help of the pendent drop method, depending on the temperature and on the surfactant added. The critical micelle concentration was reached on addition of 1% of the surfactant. A four‐component mixture consisting of HDPE, LDPE, PVC, and PS, whose composition corresponded to that of collected waste plastics, was used to study the effects of the addition of surfactants on the applicational propertie

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430105

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractHigh strength/high modulus fibres can be prepared by cold drawing of UHMW‐PE gel fibres. It is shown that the crystalline order in this fibres is not perfect. The supermolecular structure is characterized by a shish‐kebab morphology. Results of X‐ray and mechanical investigations permit to explain the drawing process by a three‐step mechanism of molecular orientation and stretching coupled with molecular and fibrillar

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430106

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractAn experimental investigation on the streaming potential and adsorption of ethyl xanthogenate ions on polyester fibres at various temperatures has been carried out. The results reveal that the uptake of ethyl xanthogenate ions by the polyester fibres in the tested temperature interval takes place with the establishment of strong chemical bonds. The results are interpreted on the basis of nucleophilic attack of the negatively charged oxygen in the carbonyl group of the polyester on the thiocarbonyl group of the xanthogenate ion.

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430107

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractDie Erhöhung der Strahlenempfindlichkeit von polymeren Resistmaterialien ist für den Einsatz in der Mikroelektronik von großem Interesse. Am Beispiel der thermischen Vorbehandlung von Methylmethacrylat‐Methacrylsäure‐Copolymeren in einer Acetophenon‐Lösung wird gezeigt, daß unter Abspaltung von Wasser und Methanol eine intramolekulare Bildung von cyclischen Anhydridgruppen erfolgt, die bevorzugt durch ionisierende Strahlung gespalten werden. Das thermische Abbauverhalten und die Bestimmung des Anhydridgehaltes werden durch kombinierten Einsatz von TG, MTA, TL und NMR

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430108

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractPfropf‐ und Copolymere aus polaren Monomeren werden hinsichtlich ihrer Synthese und Charakterisierung näher beschrieben. Im Falle der Pfropfcopolymere sind aktivierte P2VP‐, P4VP, PVAC‐ und PMMA‐Ketten die Voraussetzung für die Monomeraddition. Dabei ablaufende mögliche Reaktionen werden diskutiert. Gut definierte Blockcopolymere sind zugänglich, wenn die kurze Lebensdauer der AN‐Ketten für die weitere Monomeranlagerung ausgenutzt wird. Die Untersuchung der chemischen Uneinheitlichkeit derartiger Systeme i

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430109

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractPoly(phenylquinoxaline‐imide‐amide)s have been prepared by low‐temperature solution polycondensation of aromatic diamines containing preformed phenylquinoxaline units and amide or imide groups with diacid chlorides of certain dicarboxylic acids incorporating imide rings. These polymers are easily soluble in polar aprotic solvents and give transparent films with high thermal stability and good electrical insulation prope

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430110

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY