摘要:

AbstractPolychelates were obtained by addition of an aqueous solution of the branched poly(ethyleneimine) (BPEI) to the aqueous solutions of Cu(II), Co(II), and Ni(II). All the polychelates were characterized by elemental analysis, FT‐IR,1H NMR spectroscopy, thermogravimetry, and scanning electron microscopy. Conductivity and magnetic moment measurements were also carried out. The three polychelates showed a change of the chemical shift in1H NMR spectra due to the metal ion complexing with the polyligand. Accordingly to the spectral study, the polychelates showed different geometric arrangements: Cu‐BPEI square planar, Ni‐BPEI tetrahedral, and Co‐BPEI oct

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052380101

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe concurrent influence of the processing aid (Paraloid K 120N) and the carbon black ratio, as well as the nature and the ratio of the impact modifier (CPE 3615 and Kane Ace B56 A) on the main physico‐mechanical characteristics of the poly(vinyl chloride)‐based unplasticized mixtures have been studied. The results obtained, processed mathematically and plotted graphically in the form of response surfaces, evidenced that the improvement of certain physico‐mechanical properties becomes possible by the introduction of 2.5 parts and 5.0 parts carbon black into these compounds. This is due to the introduction of impact modifiers and processing aids into the mix

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052380102

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThis paper studies the effect produced by different vanadium oxides on the microstructure of PEO and PEO/PPO blends by means of the analysis of the crystallization kinetics under isothermal and nonisothermal conditions. The electrical properties of the samples were characterized by complex impedance analysis. Results suggest that the additives employed (considering both carbon black and vanadium oxides) promote changes in the microstructure of PEO/PPO polymer blends because of polymer‐additive interactions. All samples tested show good conductivity propertie

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052380103

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractOxymethylene‐linked 2‐vinylpyridine‐oxyethylene (2VP‐EO) mulitblock copolymers doped with LiClO4or/and tetracyanoquinodimethane (TCNQ) showed ionic electronic and mixed (ionic‐electronic) conductivity. Effects of the poly(oxyethylene) content and of the molar ratios of EO/Li and TCNQ/2VP on the conductivities of the complexes were studied. The optimum molar ratios of EO/Li and TCNQ/2VP were 10 and 1.0, respectively. The copolymers emulsified benzene/water systems and exhibited good phase‐transfer catalysis properties in the Williamson reaction of solid potassium phenolate with n‐butyl bromide. After neutralization with HCI solution, the copolymers showed polyelectrolyte soluti

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052380104

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe cationic polymerization of tetrahydrofuran (THF) initiated by 4,4′‐azobis(4‐cyanopentanoyl chloride) (ACPC) and SnCI4is described. Poly(THF) samples possessing azo gorups in the main chain thus obtained were used as initiator in the polymerization of styrene (S) and methyl methacrylate (MMA) at 70°C to yield PTHF‐PS‐PTHF and PTHF‐PMMA block copolymers. Characterization of the block copolymers was carried out by fractional precipitation, spectroscopic methods and viscosity

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052380105

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractA series of new polyhydrazides containing pendent phenoxy groups has been synthesized by low‐temperature solution polycondensation of equimolar amounts of diacid dichlorides and 2‐phenoxyterephthalic dihydrazide in N‐methyl‐2‐pyrrolidi‐none (NMP). The thermal cyclization of the polyhydrazides gave the corresponding poly(1,3,4‐oxadiazole)s containing pendent phenoxy groups. The polymers were characterized by viscometry, solubility measurements, IR spectroscopy, differential scanning calorimetry (DSC) and thermogravime

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052380106

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractAusgehend von den Grundlagen zur Kapillarrheometrie mit den bekannten Korrekturverfahren nach Rabinowitsch und Bagley wird das traditionelle Verfahren zur Ermittlung des Düseneinlaufdrucks sowie des Wandschubspannungswerts dargestellt. Dieses Verfahren kann bei manchen Materialien zur fehlerhaften Bewertung des Fließverhaltens führen, da ein linearer Druckabfall in den Meßdüsen unterstellt wird. Daher wird eine neue Methode zur direkten Schubspannungsermittlung vorgestellt sowie die dazu notwendige Meßeinrichtung beschrieben. Es handelt sich dabei um eine in‐line integrierbare Düse, die auf der Basis eines auf Piezokraftaufnehmern gelagerten Düsenabschnitts die Reaktionskraft der strömenden Schmelze auf die Düsenwandung ermittelt.Die Meßergebnisse zeigen, daß bei der Ermittlung der Fließeigenschaften von Materialien, die ein Potential zur Strukturbildung während des Fließvorganges aufweisen, wie z. B. flüssigkristalline Polyester (LCP), mit der In‐line‐Düse korrekte Wandschubspannungen erhalten werden. Mit der klassischen Methode der Kapillarrheometrie hingegen können bei solchen Materialien nur dann vergleichbare Ergebnisse gewonnen werden, wenn zusätzliche Annahmen über den Druckverlauf in d

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052380107

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe present study was carried out to examine the effectiveness of an addition of triethylaluminium totert‐butyl perpivalate which is frequently used in industrial applications for initiating the copolymerisation of ethylene with vinyl acetate. For this purpose, polymerisation tests were carried out in the laboratory on a continuous basis at 1900 bar and 150°C. Vinyl acetate was added in concentrations of up to 36 wt.‐% in the feed to the reactor. The organic peroxide concentration was 50 mole ppm; the concentration of organoaluminium alkyl was varied within the range of 0–75 mole ppm.The effects observed, namely an increase in the conversion and a decrease in the peroxide consumption were more marked than with the homopolymerisation of ethylene. This is attributable to the increased rate of chain growth in addition to the increased amount of radicals available.The properties of the copolymers obtained are changed only moderately by aluminium alkyl. Apart from a decrease in density and an increase in the melting point, a decrease in the polydispersity was ob

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052380108

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe effects of EPDM admixture, mixing conditions and additional stabilization on the phase structure and impact strength of low‐density polyethylene/isotactic polypropylene (LDPE/PP) blends were studied. It was proved that EPDM is localized at the interface between LDPE and PP phases. The admixture of 5% EPDM substantially increases impact strength of LDPE/PP blends at all the compositions. Higher intensity and longer time of mixing have a positive effect on the impact strength of the studied blends. For the blends with higher content of polypropylene it is necessary to prevent their degradation by additional stabilizatio

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052380109

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractEthylene‐vinyl acetate (EVA) copolymer (12% vinyl acetate content) is subjected to electron beam irradiation using trimethylolpropane trimethacrylate (TMPTMA) as a radiation sensitizer. Mechanical and electrical studies of these irradiated samples show that the strength properties (tensile strength, elongation at break) are increased with radiation dosage up to an optimum radiation dose and sensitizer level above which the properties begin to deteriorate. Crosslinking of the polymer takes place on irradiation which is attributed to an increased gel content with increasing radiation dose. Compared to the original samples both dielectric constant and dielectric loss factor decrease for samples subjected to irradiatio

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052380110

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY