Showing papers in "European Polymer Journal in 1979"

TL;DR: In this paper, the model proposed by Cossee for Ziegler-Natta polymerization of propene is re-examined by computing the non-bonded energies for all sets of possible internal coordinates of the atoms at the catalytic site.

TL;DR: In this paper, it was shown that poly(methylphenylsiloxane) is thermally more stable to weight loss than poly(dimethylsilyl groups) and that the stability decreases with increasing molecular weight and with replacement of terminal hydroxyl by trimethyl silyl group.

TL;DR: In this paper, the same authors studied the oxidation of polybutadiene by molecular oxygen, singlet oxygen, atomic oxygen and ozone using u.v. and i.r. spectroscopic methods.

TL;DR: The first order rate constant for pyrolysis is 1.1 × 10 −2 sec −1 at 384° with an overall activation energy of 41 kcal mol −1 as mentioned in this paper.

TL;DR: In this paper, X-ray diffraction measurements on mono-oriented fibres confirm that nylon 6 crystallizes in the monoclinic system, with crystallographic parameters: a = 9.71 A, b = 8.19 A, c = 17.40 A (fibre axis), γ = 115°, 8 monomeric units in the unit cell and space group P22.

TL;DR: The only products able to destroy hydroperoxides as rapidly as DMSD are sulphur dioxide and methyl-β-sulphinopropionate (MSP) as discussed by the authors.

TL;DR: In this paper, the rate of polymerization of acrylic acid by S2O2−8 ion in alkaline and acid conditions was investigated and the effect of ionic strength, pH and catalytic effect of Ag+ and Cu2+ on the system was discussed.

TL;DR: In this paper, the mesophasic structure of a 50/50 co-polymer was found to be nematic, and the molar isotropization entropy was shown to be relatively large.

TL;DR: In this paper, four polycarbonates of formula: have been prepared and characterized by DSC thermal analysis and X-ray diffraction methods and they show thermotropic mesophasic behavior.

TL;DR: In this article, the mechanism of hydroperoxide formation during polyolefins is discussed, and the distribution of these groups and their proportions depend on oxygen pressure and other reaction conditions.

TL;DR: In this article, a new phenoxaphosphine-containing polyamides were prepared from 2,8-dichloroformyl-10-phenylphenoxaphophosphine 10-oxide (III) and aromatic diamines in DMA by low-temperature solution polycondensation in the presence of triethylamine as acid acceptor.

TL;DR: In this article, the effects of gamma irradiation on the tensile properties and crystalline structure of isotactic polypropylene film with differing crystalline forms have been measured, compared and discussed.

TL;DR: The monomer reactivity ratios for radical copolymerizations of tributyltin methacrylate (monomer-1) was found as r 1 = 0.79 and r 2 = 1.68 as mentioned in this paper.

TL;DR: In this article, the photo-stability of 2-hydroxy-4-octyloxybenzophenone (HOBP) in the presence of possible photo-sensitizers present in polymers is investigated.

TL;DR: The mechanism of byproduct formation in the reaction of a thiol antioxidant, 3,5-di-tertbutyl-4-hydroxybenzyl mercaptan (BHBM), with rubber latices is shown in this article.

TL;DR: In this article, the structures of isoimide cycles in polyimides were elucidated from i.r. and 13C NMR spectra of N-phenylphthalimide and N-phylphthalisoimide.

TL;DR: X-ray diffraction of polyacrylonitrile (PAN), poly-2-hydroxyethyl methacrylate (poly-HEMA) and their random copolymers containing low proportions of HEMA has been carried out in order to investigate the changes in the PAN structure produced by introducing some HEMA units into the chain this paper.

TL;DR: In this article, the synthese de copolymeres trisequences polystyrene-polydimethylsiloxane-polystyrene a ete realisee par reaction d'hydrosilylation entre une molecule-modele des α,ω-dihydrogeno, polydimethylsoxanes d'une part and des sequences de polystyrone ω-vinylsilane d'autre part.

TL;DR: A kinetic investigation of the early steps of the radical copolymerization of styrene and divinylbenzene (DVB) has been performed in the presence of a transfer agent, meant to delay the onset of the gel point as mentioned in this paper.

TL;DR: In this paper, a dielectric study on polyacrylonitrile (PAN), poly-2-hydroxyethyl methacrylate (P-HEMA) and copolymers of acrylate and HEMA in the temperature range 30-150° is reported.

TL;DR: In this paper, the infrared spectra (1800-1400 or 2200-1500 cm −1 ) were studied for PVC films stabilized with Ba, Cd stearate and with their equimolar mixture, and previously subjected to thermal degradation at 180° in air, or in a few cases in nitrogen.

TL;DR: In this article, a triangular fractionation method using methanol as non-solvent was used to determine the molecular weights of polyacrylamide, and integral and differential distribution curves were plotted using the fractionation data.

TL;DR: The copolymerization of ethylene and hexene has been carried out using Phillips' catalysts modified with small amounts of triethylaluminium [Al(C2H5)3], without solvent other than hexene itself and under constant ethylene pressure as discussed by the authors.

TL;DR: In this paper, a series of linear and branched polystyrenes were obtained by a cross-linking reaction using γ-irradiation from a Co60 source.

TL;DR: Very narrow fractions of polyvinylpyrrolidone (PVP) for a range of low molecular weight from 20·103 to &{;10 3 were prepared by gel filtration using sephadex gel as discussed by the authors.

TL;DR: In this paper, a simple expression has been obtained for the change with time, t, of the difference between the radioactivity of the two faces of a disc of material made by joining a disc containing radioactive diffusant to a similar disc containing no radioactive material.

TL;DR: The phosphorus-containing polyamide-imides have good thermal stability, and are self-extinguished immediately after the flame was removed as discussed by the authors, and are fairly soluble in DMA, DMF, and conc. H 2 SO 4 ; the reduced viscosities of polymers in DMF or cone were 0.19-0.32.

TL;DR: This article computed molecular weight distributions and moments for condensation polymerizations of ARB-type monomers, where the reactions involving the monomer are characterized by a rate constant k 11 and those involving other species, by k p.

TL;DR: Sulphur trioxide is shown to be the true catalyst for peroxide decomposition as discussed by the authors, however, it becomes less active as a catalyst as a result of phase separation.

TL;DR: The preferential adsorption coefficient for the system PMMA/chloroform/methanol has been determined by GPC and from differential refractometry and interferometry measurements of dialysis equilibrium as discussed by the authors.