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The Monte-Carlo (MC) method developed to model the elastomeric stress–strain behaviour of polyethylene (PE) and poly(dimethyl siloxane) (PDMS) networks and the stress–optical behaviour of PE networks is now applied to the stress–strain behaviour of poly(ethylene terephthalate) (PET) networks. In keeping with the previous results for PE and PDMS networks, increases in the proportions of fully extended...
Polymers containing the pendant propargyl groups can be effectively crosslinked upon UV irradiation in the presence of a small amount of W(CO) 6 . The alkyne–tungsten carbonyl complex was formed initially as evident by IR spectroscopy, which was involved in the subsequent crosslinking reaction. Analyses by UV, IR, and 13 C NMR CP/MAS spectroscopic methods confirmed the polymer crosslinking...
An unconventional amphiphile (1-[ω-(4′-methoxy-4-biphenylyloxy)octyl]pyridinium bromide, PC8) was used as surfactant in the emulsion polymerization of styrene. At low surfactant concentration (6, 12 or 36 mmol l −1 ), curves of polymerization rate versus conversion obeyed the typical behavior characterized by intervals I, II and III. However, at high concentration (48 or 72 mmol l −1 ...
The guanidine ligand attached to vinylbenzyl chloride matrix as well as its sorption ability to tetrachloroaurate and dicyanoaurate ions were investigated upon using X-ray photoelectron spectroscopy. The form of metallic gold, Au(0), was not observed on gold loaded resin surface when solutions of tetrachloroaurate or potassium dicyanoaurate were used. Complete elution of gold was achieved for both...
Glassy polymer is formed because the irregular chain architecture prevents crystallisation. Computer simulations allow Voronoi tessellation of atomic groups (for example monomers) to be carried out and measured along the molecular chain, which reveals significant density fluctuations. A Voronoi polyhedron is constructed for each particle according to a unique mathematical procedure [J Reiner Angew...
The in situ variation of induced orientation within a liquid crystalline polyester under the influence of a magnetic field was investigated during heat treatment, by means of wide-angle X-ray scattering (WAXS) using synchrotron radiation. The kinetics of molecular orientation, both from the melt and from the solid state, is analyzed in a wide temperature range (T=190–260°C) in terms of the variation...
An efficient algorithm is presented for numerically evaluating a self-consistent field theoretic (SCFT) model of block copolymer structure. This algorithm is implemented on a distributed memory parallel cluster in order to solve the SCFT equations on large computational grids. Simulation results are presented for a two-component molten mixture of a symmetric ABA triblock copolymer with an A homopolymer...
Blend films of poly (o-ethoxyaniline) (POEA) and collagen were fabricated by casting under optimized conditions and characterized by Raman scattering and UV–vis absorption spectroscopies. The UV–vis spectra showed that the addition of collagen in the aqueous solution of POEA promotes a dedoping of the POEA. This effect was also observed for the blend films as supported by Raman scattering and a mechanism...
The flame retardant mechanism for silicone rubber induced by adding ppm order of a platinum compound, platinum (0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex was studied by analytical pyrolysis techniques and alkaline hydrolysis gas chromatography. The thermal degradation measurement of the flame retardant silicone rubber sample (FR-SR) indicated that a considerable amount of methane was evolved...
Departures from the geometric mean assumption for the interaction energy between unlike polymer repeat unit pairs i/j computed from experimental data, were correlated with the molecular connectivity indices for the repeat units. The effects of various factors on the correlation results were investigated. A better correlation is obtained when terms involving the solubility parameters for the repeat...
Novel double-layer delivery devices based on soy protein derived materials were designed and produced using an innovative two material co-injection moulding technique. It was demonstrated that the viscosity ratio between core and skin layer materials played an important role in the formation of the interfacial shape, namely the skin thickness and uniformity of the bi-materials. The adequate selection...
The synthesis and hydrogenation of two fluorinated polymers is described. The products were characterised through a detailed study of their 1 H-, 13 C- and 19 F-NMR spectra, together with thermal and GPC analysis. Hydrogenation resulted in a significant lowering of the glass transition temperatures of the polymers.
Semicrystalline polymers often show a spherulitic morphology, consisting of a radial assembly of twisted crystalline lamellae and amorphous layers. A multiscale numerical model is used to investigate the mechanics of intraspherulitic deformation of polyethylene. The model establishes links across the microscopic, the mesoscopic, and the macroscopic levels. Constitutive properties of the material are...
We developed a procedure for a direct evaluation of light scattering patterns registered during an isothermal crystallization of s-polypropylene. Analysis is based on the determination of three parameters of the scattering curve for both, polarized and depolarized measuring conditions: (i) the forward scattering intensity I(q→0) (ii) the width Δq of the intensity distribution (iii) the integral intensity...
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