Influence of the degree of hydrolysis of poly(styrene-alt-maleic anhydride) on miscibility with poly(vinyl acetate)

The influence of the hydrolysis of anhydride groups in poly(styrene-alt-maleic anhydride) (PSMA) on its miscibility with poly(vinyl acetate) (PVAc) is investigated. The cloudpoint curves of these blends are determined as a function of the degree of hydrolysis. The miscibility is shown to improve with increasing number of carboxylic acid groups in PSMA. Specific interaction between the acid groups of PSMA and the ester groups of PVAc, together with the so-called copolymer effect, is put forward as an explanation for this observation