Thermal and Mechanical Properties of Electron Beam Irradiated Polyvinyl chloride)/Polystyrene Blends

摘要

The effect of electron beam irradiation on the thermal and mechanical properties of polyvinyl chloride)/po!y-styrene (PVC/PS) blends and PVC/PS blends containing epoxidized natural rubber (ENR) was studied. The ther-mogravimetric analysis study showed that the thermal decomposition of the plasticized PVC individual polymer goes through two stages, whereas PS decomposes through one stage. However, the temperature of the maximum rate of reaction (T_(max)) of PS is much higher than that for PVC and their blends. Meanwhile, the T_(max) was found to increase with increasing PS ratios in the blend. The thermal stability of PVC/PS blends was greatly increased after electron beam irradiation in comparison with unirradiated blends. Moreover, the addition of ENR to PVC/PS increased the thermal stability. On the other hand, the mechanical properties in terms of tensile strength and elongation at break of PVC/PS blends are lower than pure PVC polymer because of the immiscibility. However, the addition of ENR to the PVC/PS (80/20) blend increased the elongation at break from 114 to 321% associated with a small effect on the tensile properties. These behaviors were supported by structure morphology studies observations, which indicate an improvement in the interfacial adhesion between the phases.