Showing papers in "Polymer in 1978"

TL;DR: In this paper, a method of determining the parameters characterizing the kinetics of non-isothermal crystallization on the basis of d.s.c. thermograms is presented.

TL;DR: In this article, a model involving a linear superposition of one or two phenomenologically independent first order relaxation terms upon the ideal Fickian diffusion equation was proposed to describe the individual contributions of the diffusion and relaxation processes.

TL;DR: In this article, the aqueous solution properties of an ampholytic poly(vinyl imidazolium sulphobetaine) are discussed and an explanation of its solubility in certain salt solutions is presented.

TL;DR: In this article, the influence on blend morphology of such compositional variables as molecular weight, chemical affinity and percentage of components in the blend was investigated, and the states of dispersion are affected by conditions of blend preparation and extrusion.

TL;DR: In this paper, the dynamic mechanical behaviour of ultra-high modulus polyethylene is reported in terms of a fiber reinforced composite model, in which the amount of fibre phase is related to the number of intercrystalline bridges determined from X-ray diffraction data.

TL;DR: In this paper, the transport kinetics of liquid methanol in PMMA sheet (Perspex) have been studied over the temperature range 23° to 63°C, and the authors showed that at lower temperatures the transport is typical Case II; the methanols penetrating the polymer behind a sharp front which moves at constant velocity.

TL;DR: In this article, the authors measured the thermal conductivity of oriented polyethylene both along and perpendicular to the draw direction for draw ratio λ between 1−25 and in the temperature range of 120 to 320K.

TL;DR: In this paper, the sedimentation of various spherical particles with radii 25-175 A in poly(ethylene oxide) aqueous polymer solutions have been investigated by analytical ultracentrifugation.

TL;DR: In this article, a reexamination of previous studies concerning the electrical discharge treatment of polyethylene and the resulting enhancement of autoadhesion has been carried out, and X-ray photoelectron spectroscopic data provide new insight into the phenomenon by showing surface oxidation to result from treatment in inert gases.

TL;DR: In this article, it was shown that high modulus can not require complete chain extension and can be generated by lamellar crystals, where the lamellae are all parallel and the plane normals are along the tensile direction.

TL;DR: In this article, the surface structure and wettability of polyethylene terephthalate (PET) fibres were investigated in various gases: nitrogen, oxygen, air, carbon dioxide and ammonia.

TL;DR: In this article, the resolution of normalized diffraction peaks in terms of combined Gaussian-Cauchy profiles for each peak, together with a polynomial background, is described.

TL;DR: In this paper, a series of amine-cured epoxy resin adhesives in both the bulk material and adhesive joints has been studied as a function of the formulation of the resins and the conditions of testing using a linear elastic fracture mechanics approach.

TL;DR: Fracture mechanics has been applied to the investigation of the failure of structural adhesives in humid environments as discussed by the authors, and the properties determining adhesive behaviour comprise T g, solubility parameter, surface free energy, viscosity and the microstructure of the polymer.

TL;DR: In this article, the tensile creep and recovery of oriented linear polyethylene (LPE) monofilaments have been studied for a range of samples of different structure.

TL;DR: Ledwith, A. as discussed by the authors, A. R. and A. A. C. N. Foster in 'Essays on Free Radical 20 Belgium Pat. No. 833 472; US Pat.

TL;DR: The structure of cellulose II was determined using the intensity data from Mercerized cotton fibres and rigid body least squares refinement techniques as mentioned in this paper, and the final crystallographic R value was 0.263 based on intensity data for 30 observed and 11 unobserved non-meridional reflections.

TL;DR: In this paper, the alternating mechanism of network formation in the curing of epoxy resins from bisphenol A diglycidyl ether (BADGE) and amine curing agents does not offer any special opportunity for the formation of inhomogeneities caused by partial segregation or inhomogeneous crosslinking.

TL;DR: In this article, the apparent Young's modulus of the crystalline part of a number of ultra-high modulus polyethylene drawn tapes was measured by observing the change in Bragg angle of the 002 X-ray reflection when the tapes are placed under stress.

TL;DR: In this paper, small-angle X-ray scattering was used to determine the d-spacing and the degree of crystallinity χ and by gel permeation chromatography to determine molecular weight, Mw, and molecular weight distribution.

TL;DR: A preparative gel permeation chromatographic (g.p.c.) instrument has been constructed and used to separate broad fractions of cyclic poly(dimethyl siloxanes) into sharp fractions with heterogeneity indices M w M n = 1.05 ± 0.02.

TL;DR: In this article, it has been shown that orientation of the amorphous phase promotes a substantial increase in crystallization rate, in turn depending on the crystallization temperature: the higher the temperature, the stronger is the effect of orientation.

TL;DR: The crystal structure of cellulose triacetate I (CTA I) obtained by heterogeneous acetylation of ramie cellulose I, has been determined by a combined X-ray diffraction and stereochemical model analysis as mentioned in this paper.

TL;DR: In this paper, an investigation into curing of Bisphenol A diglycidyl ether with an amine curing agent was carried out both above and below the glass transition temperature, T g, of the reacting system.

TL;DR: In this article, the authors investigated the suspension polymerization of ethylene using a highly active Ziegler-Natta catalyst and found that the monomer transport is hindered neither by pore diffusion inside the suspended particle, nor by film diffusion at the surface of the suspension particle.

TL;DR: The use of neutron scattering to study the conformation and dynamics of polymer chains in the bulk amorphous state and in solution is reviewed in this paper, where three topics covered by this review are: conformation studies of polymers; dynamics of poly chains and studies of side group motion in polymers.

TL;DR: In this article, the shape of the craze at the tip of a loaded crack has been determined by optical microscopy for polycarbonate, and the effect of temperature was examined, and measurements were made on samples of different molecular weight.