Showing papers in "Polymer in 1988"

TL;DR: In this paper, three important thermal properties of polylactides have been measured and discussed: glass transition temperature, melting temperature, and degradation behavior, and they have been found to be highly sensitive to heat, especially at temperatures higher than 190°C.

TL;DR: In this paper, the authors describe the way in which the components of complex polymer blends are segregated after melt processing and the various morphologies which are formed are shown to be consistent with those predicted from an analysis of spreading coefficients.

TL;DR: In this paper, it was shown that the two peaks in typical melting endotherms represent different components of the morphology, formed in two stages of crystallization, and that the correlation of melting point and location within the spherulite architecture is an inherent function of that location.

TL;DR: In this article, a phase diagram of poly-d (−)-3-hydroxybutyrate (PHB) and poly(ethylene oxide) (PEO) mixtures is presented.

TL;DR: In this article, the brittle-tough transition in nylon/rubber blends occurs when the yielding process propagates through thin matrix ligaments in which a plane-strain to plane-stress transition takes place.

TL;DR: In this article, the N-alkylacrylamide copolymer with eight, ten and twelve carbons on the alkyl substituent was described and its rheological properties were studied as a function of polymer concentration, electrolyte concentration, temperature and shear rate.

TL;DR: In this article, the size and size distribution of the minor phase in melt blended polypropylene/polycarbonate blends is studied as a function of composition, particularly at intermediate concentrations where the region of dual-phase continuity was observed for these blends.

TL;DR: Several new arylene ether homopolymers and copolymers have been prepared by the nucleophilic displacement of aromatic dihalides with aromatic potassium bisphenates.

TL;DR: In this article, a polypyrrole containing the toluenesulphonate counter-ion has been electrochemically polymerized on a wide range of metallic electrodes, including platinum, titanium, aluminium, mild steel and brass.

TL;DR: In this paper, the coefficients of permeability, diffusion and solubility (P, D and S, respectively) of various substituted polyacetylenes for six gases (He, H 2, O 2, N 2, CO 2 and CH 4 ) at 25°C were determined.

TL;DR: In this article, the microstructures of cured styrene-unsaturated polyester resins were studied by using scanning electron microscopy, showing that the size and structure of the microgels depend strongly on the concentration of styrene monomer.

TL;DR: In this paper, the suitability of sawdust wood residue as a filler for thermoplastics has been tested using two different mesh sizes (20 and 60), as well as by varying the weight percentage of fibres from 10% to 40%.

TL;DR: In this article, the binary interaction parameter χ eff has been obtained for deuterated polystyrene/polyvinyl methyl ether blends as a function of temperature, composition and molecular weight from small-angle neutron scattering experiments.

TL;DR: In this article, the effects of crosslink density on the glass transition temperature, Tg, and the change in specific heat ΔCp at Tg were measured using a differential scanning calorimeter (d.s.c.).

TL;DR: In this article, the authors studied the crystallization behavior of poly(p -phenylene sulphide) (PPS) in terms of linear crystal growth rates and overall rates of bulk crystallization as functions of molecular weight and temperature.

TL;DR: The morphology of two new high performance polymer fibres, rigid-rod poly(p -phenylene benzobisoxazole) (PBO) and stiff-chain poly(2,5(6)-benzoxazoles) (ABPBO), has been examined by wide angle X-ray scattering and scanning and transmission electron microscopy as mentioned in this paper.

TL;DR: In this paper, it was shown that poly(4-vinylpyridine) is compatible with a copoly(styrene-4-hydroxystyrene) containing 50 mol% of 4-hydroxstyrene units over the entire range of blend composition.

TL;DR: The growth, isolation and examination of individual melt-grown polyethylene is reported in this article, showing a sector boundary along their length, and distinct sectors differing very slightly in orientation across this boundary, have been revealed in dark-field electron microscopy.

TL;DR: In this paper, the authors obtained projections of a styrene-butadiene-styrene (SBS) copolymer (30 wt% styrene) at tilt angles ranging from −61.5° to +48.5 degrees in 5° increments.

TL;DR: In this article, the crosslinking mechanism of polyvinyl alcohol in the presence of boric acid was investigated by means of 11B nuclear magnetic resonance (n.m.r.).

TL;DR: In this paper, the limits of solid state order which are physically possible on cooling thermotropic random copolymers from the liquid crystalline phase were investigated using a two dimensional computer modelling routine.

TL;DR: In this paper, critical reflection experiments were performed for the interface between polystyrene and poly(methyl methacrylate) and it was shown that the interfacial mixing is not greater than 20 ± 5 A.

TL;DR: In this paper, the formation and growth of polythiophene films on platinum electrodes has been undertaken using cyclic voltammetry, a square-wave potential and polarization at constant potential.

TL;DR: In this article, the degree of cure of a poly( N, N ′-bis(phenoxyphenyl)pyromellitimide)-type polyimide has been observed to have a profound influence on the fluorescence of films irradiated in the near-ultra-violet to visible regions.

TL;DR: In this article, the authors used the Couchman-Karasz equations to fit the data well provided a variable fraction of sorbed water was taken to be active in depressing the glass transition temperature.

TL;DR: In this paper, a comparison of the stability of the conductivity of organic salts like TTF/TCNQ and those based on polyacetylene, polypyrrole, polythiophene and polyaniline with carbon black and carbon fibres, which are conductive in their neutral state, gives rise to the assumption that carbenium ion-structures are not stable with respect to the attack of oxygen and water.

TL;DR: In this article, an extended Gordon-Taylor equation was proposed to describe the glass transition in compatible polymer blends, where both the effective contact probabilities of the blend components and the effect of molecular surroundings on the contact contribution to the transition were considered.

TL;DR: In this article, it has been shown that atactic polystyrene is the consequence of liquid-liquid phase segregation arrested by vitrification in accordance with the scheme of Arnauts and Berghmans [1], in this cajse for cyclohexanol as solvent.

TL;DR: In this paper, the gel-sol transition of polyvinyl alcohol (PVA)-borate aqueous solutions was investigated as a function of polymer concentration, molecular weight, boric acid concentration and pH.

TL;DR: In this paper, an extension of Flory's theory of the expansion parameter to the case where macromolecules contain segments that can associate in an intramolecular fashion is presented.