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Polar monomers are often grafted onto poly(ethylene-co-octene) [POE] to expand its application spectrum. However, the process frequently involves cautious handling of reactive monomers and hazardous solvents. On the contrary, the present work deals with similar modification but using a polymer, poly(ethylene-co-vinyl acetate) [EVA] in the melt through the formation of a double network hybrid using an external crosslinker. POE is an important new generation elastomer having great balance between physical and mechanical properties but its polarity needs to be improved for furthering its uses in industrial oil resistant applications and surface adhesion with other agents. The POE (major component)-EVA (minor component) hybrid compositions were designed using Taguchi statistical technique for optimization. Physico-mechanical properties like tensile, stress relaxation, hysteresis, rheological properties like pseudoplastic index, die swell and solvent swelling kinetics were investigated. The results were found depended on the network morphology of the hybrids. One composition was finally selected which produced better balance between all physico-rheological properties. [ABSTRACT FROM AUTHOR]

This paper demonstrates interesting contrasts between physical, mechanical and rheological properties of double network hybrids developed from high (30 wt.%) and low (9 wt.%) methyl acrylate containing poly (ethylene-co-methyl acrylate) and poly (ethylene-co-octene) thermoplastic elastomer. The compositions were designed adopting a Taguchi L9 statistical model. The model was espoused to consider a wide range of blend compositions and process conditions for optimization. The majority of the low methyl acrylate containing hybrids showed normal correlation between mechanical and other physical properties with the net gel content while for the other variety, they were ambiguous. The reason was investigated and it was found to be due to the influence of the nature of crosslinks formed between the phases which controlled the properties in the latter. Based on the results, finally, two blend compositions were chosen from each set as the most optimized formulations for future study. [ABSTRACT FROM AUTHOR]

This is the first report on the use of waste chrome-tanned Indian leather buffing dust for plasticizing atactic polystyrene (PS). There is no effective re-use of waste leather buffing dust reported till today. This waste material, after preliminary characterization, has been dispersed in solvated polystyrene. Resultant composites prepared therefrom via solution cast method exhibit a drastic drop in surface hardness up to certain modifier concentration, beyond which it increases. Addition of surfactants during dispersion of the buffing dust at the optimum level further reduces surface hardness. Para-toluene sulphonic acid (PTSA) has been found to be a better compatibilizer than more conventional sodium lauryl sulphate (LS) in this system. The compatibilized composites show substantial "yield behaviour" when stretched and the breaking strain has been improved drastically from 0.2% in pure polystyrene to 25% in PTSA compatibilized system without any loss in strength. Accordingly, the breaking energy has been increased to much greater than that of the virgin polymer. Effective plasticization of the composites has lowered the glass transition temperature (Tg); PTSA containing composite has shown the minimum value, possibly due to generation of more free volume around the rigid polystyrene molecules on account of its effective adsorption over finer dust particles. Accelerated thermal degradation study shows greater thermal stability of the composites as compared to virgin polymer and this possibly resulted due to the presence of chromium content in the waste, which acts as heat sinks. [ABSTRACT FROM AUTHOR]