Showing papers in "Polymer in 1986"

TL;DR: In this article, a study has been made of the crystallization behavior of poly(ether-ether-ketone), PEEK, under isothermal and non-isothermal conditions.

TL;DR: A theory of rubber elasticity based on the concept of entanglements was presented in this paper, where it was shown that for small deformation the molecular mechanism of stretching is dominated by the slippage of chains.

TL;DR: In this paper, the phase behavior and solution properties of a homopolymer based upon a recently available sulphobetaine monomer, N -(3-sulphopropyl)- N -methacrylooxyethyl- N, N -dimethyl ammonium betaine (SPE), were investigated at the molecular level by static and dynamic light scattering, as well as laser Raman spectroscopy.

TL;DR: In this paper, differential scanning calorimetry (d.s.c.) and gel permeation chromatography (g.p.c) were used to study the thermal degradation of 4,4′-diphenylmethane/1,4-butanediol based monodisperse urethane model compounds.

TL;DR: In this article, the authors examined the initial stages of polymer crystallization in the melt, registered in situ by time-resolved small-angle X-ray scattering using a synchrotron Xray source, and found that the NIF state had a more disordered layer surface as compared to the final E and F2 structures.

TL;DR: In this article, an analysis of the dichroic ratios of the main infra-red-active modes for a poly(phenylene vinylene), PPV, was carried out and the authors obtained an orientation parameter s = 0.04, corresponding to a value of 0.94 for the Hermans orientation function.

TL;DR: In this article, a permanganic etchant based on phosphoric acid was used to study the morphology of PEEK under the electron microscope, revealing differences between specimens crystallized at different temperatures.

TL;DR: In this article, the morphology of poly(aryl-ether-etherketone) (PEEK) has been studied using optical microscopy (at room temperature and at elevated temperatures), small-angle light scattering (H v and V v ), transmission electron microscopy(bright field, dark field, and selected area electron diffraction), and wide and smallangle X-ray scattering.

TL;DR: In this paper, the primary nucleation of spherulites in blends of isotactic polypropylene (iPP) with high-density polyethylene (HDPE) was investigated by means of differential scanning calorimetry and optical microscopy.

TL;DR: In this article, the melting behavior of poly(aryl-ether-etherketone) was investigated using Fourier transform infra-red (FTir) spectroscopy and differential scanning calorimetry (d.s.c.) as part of a study of a carbon fibre reinforced PEEK composite.

TL;DR: In this article, the annealing time dependence of enthalpy relaxation of a sample of polycarbonate pre-annealed at various temperatures close to the glass transition temperature, Tg, is investigated over an extended range to check the consequences implied by a previous treatment.

TL;DR: In this article, two kinds of processing have been used: (a) one-step mixing in which the three components were simultaneously introduced in the mixer; (b) two-stage mixing in where the two rubbers EPM and EPM-g-SA were separately premixed before the final mixing with PA6.

TL;DR: In this article, a brittle-ductile transition was observed in the Kc−T curve of poly(ether ether ketone) (PEEK) and its short glass-fibre reinforced composite.

TL;DR: In this paper, the conductivity of different polypyrrole salt films has been varied by treatment with NaOH and H2SO4 and it was shown that the chemical treatments cause ion exchange processes which are almost completely reversible.

TL;DR: In this article, random copolymers containing 58% 4-hydroxybenzoic acid and 42% 2-hydrox-6-naphthoic acid are able to display a three dimensional order with a degree of crystallinity of more than 60% The crystals are far from being perfect: their enthalpy and entropy of transition are 10-20 times smaller than expected for a perfect crystalline state and the volume change on transition is negligible.

TL;DR: The dielectric relaxation behavior of a liquid crystalline side-chain polymer having a siloxan backbone to which is attached an aromatic ester group via a C 5 methylene spacer has been studied in the nematic and isotropic phases as discussed by the authors.

TL;DR: In this paper, the dielectric permittivity and loss of poly(propylene oxide) of molecular weight 4000, PPO(4000), have been measured in the temperature range 77K-305K and frequency range 10−2 −2 × 105 Hz.

TL;DR: In this paper, the level of extractables, crystallinity, unit cell parameters and other structural information have been obtained for low density polyethylene crosslinked using weight fractions of dicumyl peroxide from 0.9 to 6.8%.

TL;DR: A detailed study using d.c. as mentioned in this paper of the melting behavior of isotactic polypropylene isothermally crystallized from the melt has been carried out, where the origin of multiple fusion endotherms was sought.

TL;DR: In this article, the authors investigated the molecular mechanism leading to phase separation and concluded that the important factor is the direct molecular interaction between the monomeric units of two polymers, which should be effectively repulsive for phase separation to occur.

TL;DR: Fracture mechanics tests on two low density polyethylenes and two linear low-density polyethylene are described in this article, showing that at temperatures < 0°C crack growth occurs.

TL;DR: In this article, a poly(acrylic acid) containing 15 mole% pyrene groups in side chains [P(H)] was prepared by a free-radical initiated copolymerization of acrylic acid and 2-[4-(1-pyrene)]butanoylaminopropenoic acid.

TL;DR: In this paper, the Gordon-Taylor-Wood, Johnston and Barton equations have been applied to predict the glass transition temperatures, Tg of vinylidene fluoride-hexafluoropropene copolymers and VDF-HFP-tetrafluoroethene (TFE) terpolymers.

TL;DR: In this article, the authors investigated macromolecule self-diffusion in poly(ethylene glycol)s with Mn = 3 × 102 to 4 × 104 and MwMn ≈ 1.1 by pulsed field gradient nuclear magnetic resonance.

TL;DR: In this article, the degree of crystallinity of poly(ethylene terephthalate glycol) (PET) obtained by induced crystallization during stretching of amorphous PET films is related to the amorphus orientation of the samples.

TL;DR: This article showed that if the corona discharge treatment power level is kept low enough, few water-soluble species are created; 4% of oxygen is added to the surface with dry-air corona; 75% of the oxidation products are identified as hydroperoxy, epoxy, hydroxyl, carboxylic acid and isolated carbonyl species.

TL;DR: In this paper, the dynamics of melts of homopolymer mixtures and copolymers are studied with RPA and the first cumulant and the zeroth-order time moment of the measured dynamic scattering function S(q,t) are expressed-in terms of their counterparts in the non-interacting system of bare chains.

TL;DR: In this paper, the authors constructed a temperature-concentration diagram of a star-branched macromolecule solution using scaling concepts, taking into account the quality of the solvent, solution concentration, the rigidity of star branches, their number and degree of polymerization into account.

TL;DR: In this paper, small-angle X-ray scattering using correlation function analysis was used to investigate the morphological changes during the premelting of linear polyethylene and showed that the thickness of the amorphous regions showed a reversible change with temperature, which indicates presence of a local equilibrium state.

TL;DR: In this paper, a model compound of poly(ethylene terephthalate) (PETP) is used to simulate the behavior of PETP in the presence of an organic acid salt, sodium o-chlorobenzoate (SOCB).