Showing papers in "Polymer in 1977"

TL;DR: In this article, the authors focused on the interpretation of three essential aspects of the thermal conductivity K of polymers: the temperature dependence, the crystallinity dependence and the orientation effect.

TL;DR: In this article, surface energy and fracture mechanics relations were applied to the analysis of bioadhesion and biocompatibility of biomaterials and implant surfaces, showing that a strongly adsorbed plasma protein film on the implant surface provides the best blood compatibility and low thrombogenic effects.

TL;DR: In this paper, a detailed comparison of the infra-red and Raman spectra of poly(trimethylene terephthalate) (3GT), poly(tetramethylene Terephthalates) (4GT), and poly(ethylene polyethylene 2GT) (2GT) is reported.

TL;DR: In this paper, the effect of particle size on the rate-determining transport mechanism controlling n-hexane sorption into polystyrene spheres was determined by monitoring the kinetics of nhexane vapour absorption in two powder samples of distinctly different narrow particle size distributions.

TL;DR: The angular dependence of the intensity of neutron scattering by deuterated polyethylene chains (PED) dispersed in the protonated host (PEH) in the semicrystalline state has been computed over the scattering range 0 A −1, where μ = (4π/λ)sin(θ/2) as discussed by the authors.

TL;DR: In this article, the authors measured the particle dimensions in blends of low density polyethylene (PE) and polystyrene (PS) made by mixing in the molten state and have been shown to depend on the viscosity of the mixed system.

TL;DR: In this paper, the propagation of cracks in epoxy resins has been studied using a linear elastic fracture mechanics approach and a double torsion testing geometry, and cracks are found to propagate in an unstable "stick-slip" manner at high temperatures and with low rates of testing whereas at lower temperatures and using higher rates of loading propagation is more stable and cracks propagate in a continuous manner.

TL;DR: The melting behavior of drawn poly(ethylene terephthalate) bristles has been studied by means of differential scanning calorimetry as discussed by the authors, and the wide-angle X-ray diffraction pattern was analyzed.

TL;DR: In this paper, the dilute solution properties of two aromatic polyamides, poly(1,4-phenylene terephthalamide) (PPDT) and poly( p -benzamide)(PBA) in 96% sulphuric acid, have been investigated by measurements of the intrinsic viscosity, by light scattering and by gel permeation chromatography (g.p.c.).

TL;DR: In this article, specific volumes of a series of anionic polystyrenes (M = 2000 to 2 000 000) have been measured dilatometrically over the temperature range −30° to 210°C.

TL;DR: In this paper, the synthesis of monomeric vinylimidazolium sulphobetaines, a class of aromatic inner salt monomers, their free radical polymerizations, and the properties of the resulting polymeric inner salts were discussed.

TL;DR: In this article, the limiting viscosity numbers of ten cyclic and ten linear poly(dimethyl siloxane) fractions have been measured in a π-solvent (butanone at 293K) and in two ‘good’ solvents (toluene and cyclohexane at 298K).

TL;DR: In this article, a model for diffusion-controlled sorption in polymer powders consisting of uniform spherical particles is presented, and a simple modification of the model satisfactorily accounts for the effect of particle non-uniformity upon sorption kinetics for conditions under which transport is diffusion controlled.

TL;DR: The differences between the experimental procedures which have been used to determine these structures are critically discussed in this paper, where it is shown that the unit cell parameters obtained by the various investigators for the relaxed (or α) form do not differ significantly.

TL;DR: In this paper, the thermal conductivity of semicrystalline polymers, regarded as two-phase materials, is discussed in terms of the Maxwell model generalized to the case where the inclusions are thermally anisotropic.

TL;DR: Amphiphilic graft copolymers have been synthesized as mentioned in this paper, which exhibit a narrow molecular weight distribution and are homogeneous in composition and the degree of grafting is high.

TL;DR: In this paper, an empirical relationship was established between functions of rib spacing ( r ) and fracture surface energy (γ) for poly(methyl methacrylate) (PMMA) with a molecular weight of 1.2 × 10 6 and 2.6 × 10 3.

TL;DR: In this article, it was shown that small deviations from a statistical distribution lead to anomalous features in the SANS patterns, and these features have been used to study the aggregation (clustering) process.

TL;DR: In this paper, the diffusion coefficient of polystyrene in tetrahydrofuran has been determined as a function of concentration c for the molecular weight range of 2.04 × 104 to 1.8 × 106.

TL;DR: The shape of the craze at the tip of a slowly moving crack has been determined by optical microscopy for poly(methyl methacrylate) over the range of temperatures −30° to +45°C.

TL;DR: In this article, itaconic acid was polymerized by both bulk and emulsion techniques to produce a series of samples with ester chain lengths ranging from methyl to hexyl, which were characterized by measuring the molecular weight, density, glass and sub-glass transitions.

TL;DR: In this article, a method for transforming living anionic polymers into polymeric cations via a stable intermediate stage was described, which involves termination with excess xylylene dibromide, and subsequent reaction of the polymeric product with an appropriate silver salt in the presence of a second monomer.

TL;DR: Raman active longitudinal acoustic modes have been observed in perfluoro n-alkanes and in a random copolymer of tetrafluoroethylene and hexafluoropropylene (TFE-HFP) as mentioned in this paper.

TL;DR: In this article, the spectrum of isotactic polypropylene in the preferred 3 1 helical conformation and in the irregular conformations of the amorphous phase have been isolated from the spectrum using the absorbance subtraction technique.

TL;DR: In this paper, electron paramagnetic resonance (e.p.r) was used to study the adsorption of PVP and PMMA on carbon and silica, and compared the results with both n.m. l.r and i.r.

TL;DR: A review of theoretical and experimental work on the single screw extrusion process for polymers is given in this paper, where a detailed consideration is given to the many published theoretical models of solids conveying, melting and melt flow in the channel of a plasticating extruder.

TL;DR: In this paper, the phase separation temperature of poly(ethylene glycol) (PEG) in water-sodium chloride (NaCl) and in waterpropionic acid salt (Pro-Na), with molecular weights of Mη = 2.18 × 103, 8 × 103 and 719 × 103 over concentration ranges from 0-1.09 M NaCl and 1.02 M Pro-Na.

TL;DR: In this paper, the effects of structural factors on the ease with which polymers of high molecular weight could be obtained were examined and found to correlate with previous data concerning functional group reactivities.

TL;DR: In this paper, a dynamic mechanical study of four blends of PVdF and PMMA plus the constituent homopolymers indicates that these two polymers are partly compatible, but that a crystalline PVdf phase also exists.