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Showing papers in "European Polymer Journal in 1989"


Journal ArticleDOI
TL;DR: In this paper, a copoly with relatively low molecular weight (M n ) was synthesized by direct copolycondensation without catalyst in an atmosphere of nitrogen at 200°C, to evaluate the difference in degradation between crystalline and amorphous copolymers.

218 citations


Journal ArticleDOI
TL;DR: In this article, some characteristics of photoiniferters of living radical polymerizations with tetraethylthiuram disulphide, benzyl N, N-diethyldithiocarbamate, p -xylylene bis(N, N -diethynectric acid) and tetrakis(N, N -decaramyl) benzene as photoinifiers are described and discussed.

124 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of molecular aggregation on emission behavior have been studied, together with the u.v.vis absorption spectra and DSC measurements, for several polyimides (PIs) prepared by the combination of biphenyltetracarboxylic dianhydride (BDA), pyromellitic dian hydride or benzophenonetetrarsetraconylic diyanhydride with p-phenylene diamine (PPD) or 4,4′-diaminodiphenyl ether.

122 citations


Journal ArticleDOI
TL;DR: The grafting of acrylic acid on radiation peroxidized Teflon-FEP films exhibits features differing from those observed when grafting the monomer on polyethylene films as discussed by the authors.

98 citations


Journal ArticleDOI
TL;DR: In this paper, a copolymerization of a hydrophobic monomer viz. 2-hydroxypropyl methacrylate (HPMA) and a cross-linking monomer, viz. polyethylene glycol No. 600 dimethacrylated (14G), using γ-rays from a 60 Co source was investigated.

92 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that traces of HBr or HCl do not initiate cationic polymerization of l,l-l -lactide, but they play the role of co-initiators.

77 citations


Journal ArticleDOI
TL;DR: In this article, the rate constants of propagation kp were determined from the points of inflection in the GPC-curves while kp2/kt was calculated from the product of rate of polymerization and P w.

73 citations


Journal ArticleDOI
TL;DR: In this paper, five kinds of aromatic polymers [polycarbonate(PC), polyarylate(PAR), polyetherimide(PEI), polysulfone(PSF), polyhetesulfone (PESF), and polyethersulfonesulfone-parses (PSF) were degraded at 380° in vacuum and the molecular weights and molecular weight distributions of degraded samples were measured by gel permeation chromatography.

63 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that poly(ethylene oxide) (PEO) of molecular weight (Mw) ca 5 × 106 and its complex with NaCNS have been thermally degraded at temperatures in the range 320-330°.

57 citations


Journal ArticleDOI
TL;DR: In this paper, a soluble polyimide (P12080) was thermally and thermo-oxidatively degraded and crosslinking was found to proceed under both conditions.

55 citations


Journal ArticleDOI
TL;DR: In this paper, the authors used 1H-NMR with polymerization in situ to determine the extent of reaction, pT, the composition of the remaining comonomer mixture, f2, and the copolymer composition, F2.

Journal ArticleDOI
TL;DR: In this article, the authors determined the weight conversion at the gel point (αGw) by the gas bubble method in two sets of polyacrylamide (PAA) gels crosslinked with N,N′-methylene-bisacryamide (BA) and showed that αGw remained practically constant when the crosslinker ratio was C = 10% (w/w) and the total concentration of comonomers in the feed ranged from CT = 5 to 10 g/100 ml.

Journal ArticleDOI
TL;DR: The light-induced initiation of the cationic polymerization of the diepoxide (3,4-epoxycyclohexylmethyl)-3′,4′-equilibria-carboxylate (EEC) and of n-butylvinyl ether was investigated in the presence of Ph2I+PF6− and 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TMDPO) or 2, 6-dimethoxybenzyl-ldimethoxy-phosph

Journal ArticleDOI
TL;DR: In this paper, the rate and degree of polymerization have been measured, as well as the composition of the copolymer formed, as a function of conversion, at low conversion, the first order rate constants for AIBME decomposition in STY and MMA were determined.

Journal ArticleDOI
TL;DR: The dependence of the kp-values on monomer feed composition is in great disagreement with the terminal model and can be understood in terms of a penultimate model, e.g. the one suggested by Fukuda et al. as discussed by the authors.

Journal ArticleDOI
TL;DR: Partitioning of low molecular weight species, such as oligomers, during melt blending is shown to contribute to relative shifts in recorded glass transition temperatures for immiscible blends of bisphenol-A polycarbonate and styrene/acrylonitrile copolymers.

Journal ArticleDOI
TL;DR: In this paper, a semi-efficient vulcanisation (semi-EV) system was used for epoxidised natural rubber (ENR) with or without the presence of γ-mercaptopropyltrimethoxysilane (A-189) and bis(triethoxymilylpropyl) tetrasulphide (Si-69) and cure times were studied.

Journal ArticleDOI
TL;DR: In this article, a relation for the radius of a droplet arising during mixing of polymer blends in the steady state was derived using a general description of break-up and the Smoluchowski theory of coalescence of droplets.

Journal ArticleDOI
TL;DR: In this paper, a direct numerical analysis of the triad fractions for the styrene-acrylonitrile copolymerization in terms of the penultimate model has yielded the reactivity ratios and their joint confidence regions for the bulk polymerization at 60°.

Journal ArticleDOI
TL;DR: In this article, a qualitative analysis of the conductivity of linear segmented polyurethanes is presented, showing that the conductivities depend on the hard segment concentration and the degree of phase separation exhibited by these materials.

Journal ArticleDOI
TL;DR: The kinetics of gelation have been studied complexometrically at temperatures between 25 and 40° as discussed by the authors, where the initial part was fast and curved significantly at early times followed by a decrease in the rate of exchange at longer times.

Journal ArticleDOI
TL;DR: In this article, the effects of mixing method, blend ratio, loading and type of carbon black and two other vulcanization systems on cure characteristics and mechanical properties were examined, showing that ENR behaves more like SBR than natural rubber.

Journal ArticleDOI
TL;DR: In this paper, a comparison of relative reactivities of MPTMS, methacryloxypropyl trimethoxy silane, dimethylphenyl silane and trimethyl silane has been made, and the influence of silicon comonomer on the properties of copolymers such as solubility and thermal behaviour, was also studied.

Journal ArticleDOI
TL;DR: In this article, the influence of reprocessing by injection molding on physical properties of bisphenol-A polycarbonate has been studied by means of traction and impact tests.

Journal ArticleDOI
TL;DR: In this article, the authors used NMR spectrometers to identify and assay residual unsaturation in the cure of ethylene glycol dimethacrylate, and distinguish between monomer molecules and pendant double-bonds.

Journal ArticleDOI
TL;DR: In this paper, the role of initiator-derived functionality in the thermal degradation at 300°C was evaluated using 13C-labeled initiators and 13C NMR spectroscopy.

Journal ArticleDOI
TL;DR: In this paper, three-dimensional network formation in the copolymerization of methyl methacrylate with trimethylolpropane trimethacrylated (TMPMA) is discussed.

Journal ArticleDOI
TL;DR: In this article, the average molecular weights and the molecular weight distributions of degraded samples were measured by means of GPC to evaluate the quantum yields of chain scission and crosslinking.

Journal ArticleDOI
TL;DR: In this article, the mechanical properties of blends of low density polyethylene with nylon-6 as a function of the composition are presented. But both a theoretical model and scanning electron microscopy seem to indicate some degree of interaction at high content of nylon.

Journal ArticleDOI
TL;DR: In this article, composite latex particles based on natural rubber latex have been synthesized to yield materials which may be formally regarded as interpenetrating polymer networks and semi-interpenetrated polymer networks.