THERMAL-BEHAVIOR OF POLYMER BLENDS - A COMPARISON OF THE THERMAL-PROPERTIES OF MISCIBLE AND IMMISCIBLE SYSTEMS

Thermal behaviours of poly(vinyl chloride)/poly(ethylene-co-vinyl acetate) (PVC/EVA), poly(vinyl chloride)/poly(styrene-co-acrylonitrile) (PVC/SAN) and poly(ethylene-co-vinyl acetate)/poly(styrene-co-acrylonitrile) (EVA/SAN) blends were investigated by thermogravimetric methods. For the completely miscible PVC/EVA system, blending considerably improved the thermal stability. Both the initial decomposition temperature and the overall thermal stability of PVC are improved by the addition of EVA. However, in the case of PVC/SAN and EVA/SAN blends, the effect of blending on thermal stability is much less. Attempts have been made to correlate the thermal properties with compatibility of the systems.