Showing papers in "Polymer in 1992"

TL;DR: In this article, a method of preparation of strong polyvinyl alcohol (PVA) hydrogels was developed without utilization of chemical crosslinking or other reinforcing agents, and the results showed that the gel compliance was relatively constant over a wide range of stresses and decreased as the number of freezing-thawing cycles increased.

TL;DR: In this article, the relationship between the miscibility and transesterification in the individual blend pairs is detailed in a review, including polyester liquid crystals, and a variety of polyester blends are discussed.

TL;DR: In this article, the authors measured the solubility and permeability coefficients for gases in a series of fluorinated and non-fluorinated polyimides to investigate the effects of chemical structure on permeability and permselectivity.

TL;DR: In this paper, the authors studied the kinetics of photopolymerization of dimethacrylates with the camphorquinone (CQ)/amine pair and found that only amines with an abstractable proton on the α-carbon undergo significant rates of polymerization.

TL;DR: In this article, the effect of styrene-(ethylene-co-butylene)-styrene (SEBS) and maleic anhydride (MA) functionalized version on nylon-6 was examined and compared with a conventional maleated ethylene/propylene elastomer.

TL;DR: In this paper, the crystallization conditions for the preparation of different modifications of the orthorhombic form (β form) of syndiotactic polystyrene (s-PS) are described.

TL;DR: In this article, the structure of starch in its native state and during gelatinization was studied using small-angle X-ray scattering (SAXS), and the scattering data were then modelled by considering the theoretical scattering from a finite number of infinite lamellar planes of crystalline and amorphous material, embedded in a medium of specified electron density.

TL;DR: In this article, the formation of molecular composites by the in situ polymerization of tetraethoxysilane in various organic polymers has been studied, and the results show that highly homogeneous, transparent composites can be formed for polymers such as poly(methyl methacrylate), poly(vinyl acetate), poly (vinyl pyrrolidone), and poly (N,N-dimethylacrylamide).

TL;DR: In this article, the properties of composites resulting from the formation of a cross-linked inorganic network via the polymerization of tetraethoxysilane (TEOS) in situ in a poly(methyl methacrylate) (PMMA) binder were investigated.

TL;DR: In this article, the glass transition temperature (Tg) of polyaniline films in emeraldine base form was determined and characterized for the first time to be in the range of ∼ 105-220°C for the films containing ∼ 16-0% of 1-methyl-2-pyrrolidinone (NMP) residual solvent, respectively.

TL;DR: In this paper, a novel thermoforming processing route has been developed that produces a microporous form of ultra high molecular weight polyethylene that demonstrates large negative Poisson's ratios.

TL;DR: The authors reviewed recent progress in the study of gelatin gels and found that gel junction zones do not have a large cross-sectional radius of gyration, and both the modulus and absolute optical rotation appear to increase slowly, but without limit, even when plotted on a log time axis.

TL;DR: In this paper, a series of blends were prepared by adding a polyetherimide, in varying proportions, to a trifunctional epoxy resin, triglycidylparaaminophenol, cured with 4,4′-diaminodiphenylsulphone.

TL;DR: In this paper, a series of polymerization initiated with tin methoxides were analyzed by 1H and 13C n.m.r. spectroscopy on the basis of tetrad effects.

TL;DR: In this paper, a new finding is reported concerning some structural change in the amorphous state of the polymer which occurs during the so-called induction period before the start of crystallization.

TL;DR: The features of the crystallization of syndiotactic polystyrene were investigated by X-ray diffraction, differential thermal analysis, thermogravimetry and density measurements.

TL;DR: In this paper, atomic force microscopy images of the surface of the highly crystalline cellulose microfibrils were obtained at atomic resolution under ambient conditions; the images showed periodicities along the micro-fibril axis of 1.07 and 0.53 nm that may correspond to the fibre and glucose unit repeat distances.

TL;DR: In this paper, the authors investigated the physical properties of poly(l-lactic acid (PLLA) and showed that a decrease in molecular weight increases the magnitude of the enthalpy relaxation at the glass-to-rubber transition.

TL;DR: In this article, the structure, crystallization and morphology of poly (aryl ether ketone ketone)s (PEKKs) prepared from diphenyl ether (DPE), terephthalic acid (T) and isophthalic acid(I) and having different T/I ratios have been investigated.

TL;DR: In this paper, the photopolymerization kinetics of four bisphenol-A based dimethacrylate resins were studied from −40 to 160°C by isothermal differential scanning calorimetry.

TL;DR: In this article, the mechanical behavior and morphology of films prepared from poly(ethylene terephthalate), poly(butylene-terephthalates) and polyamide-6 blends subjected to zone drawing and annealing with fixed ends are studied.

TL;DR: In this article, optical microscopy has been used to measure the growth rate of spherulites in polypropylene (PP) and isothermal d.s.c. measurements have been made of the crystallization of the PP filled with talc, calcium carbonate and stearate-coated carbonate at different loading levels.

TL;DR: In this article, the mechanism of direct oxidation of 3-alkylthiophenes using ferric chloride (FeCl3) as the polymerization oxidant/catalyst was reported.

TL;DR: In this article, the effects of branching on the yield of polyethylene have been investigated using three polymethylene samples with differing degrees of short-chain branching and the experimental results have shown the existence of double yield points for all three samples.

TL;DR: In this paper, the effect of triblock copolymers of the type styrene-(ethylene-co-butylene)-styrene and a maleic anhydride functionalized version (SEBS-g-MA) was examined and compared with the behavior reported for nylon-6 in the accompanying paper.

TL;DR: In this paper, star-shaped copolymers having three different branches, poly(styrene), poly(dimethylsiloxane), and poly(tert-butyl methacrylate), were prepared by coupling of poly((styryl) anion with end-reactive poly (dimethylsoxane) followed by anionic propagation of tert-butyyl methACrylate, and the resultant polymers were characterized by osmometry, g.p.m.c., 1 H-n.r.

TL;DR: In this paper, the gas sorption and transport properties of a series of polysulphones with tetramethyl ring substitution are reported, and the effect of the substituents on chain mobility and chain packing has been related to the gas transport properties.

TL;DR: The aggregation states of a series of comb-shaped polymers with perfluoroalkyl side chains were investigated in this paper, where the main chains were poly(fumarate), poly(acrylate) and poly(methacarithm) with side chains.

TL;DR: In this article, a rigorous test of theoretical treatments for diffusion-limited oxidation was completed by conducting an extensive series of radiation-initiated oxidation experiments on a commercial EPDM material.

TL;DR: In this paper, the cure of tetraglycidyl-4,4′-diaminodiphenylmethane with 27 wt% diaminodiphylsulphone at 160°C was studied using near i.r. spectroscopy.