Miscibility of PVC/EVA hydrolysed blends by viscosimetric, microscopic and thermal analysis

The miscibility of PVC and hydrolysed EVA was investigated by viscosimetric, microscopic and thermal analysis. EVA with 20 and 40% molar acetate groups were submitted to alkaline hydrolysis. Partially hydrolysed products with different properties were obtained, when the hydrolysis degree was varied. The crystallinity and the melting point of hydrolysed products depend on the hydrolysis degree. Our results have led us to conclude that, when the hydrolysed product has a molar ratio of 1:1 in acetate: hydroxyl groups, their blends with PVC are miscible. The miscibility, observed by three different techniques, was explained as a result of synergistic effect, due to the presence of hydroxyl and acetate groups in a molar ratio of 1:1. Under this condition, we proposed that repulsive interactions of-OH and -Ac groups are stabilised by chlorine atoms of PVC polymer. (C) 1997 Elsevier Science Ltd.