Preparation of poly(vinyl alcohol) as the dispersant for suspension vinyl chloride polymerizations

Abstract The study of the influence of the reaction conditions of alkaline catalysed methanolysis or hydrolysis of methanolic poly(vinyl acetate) (PVAc) solution shows that for PVAc with an average degree of polymerization of ∼1140 the optimal degree of hydrolysis for use as a dispersant in the suspension polymerization of vinyl chloride is ∼71 mol%. Also, the cloud point of aqueous solutions with 1 wt% poly(vinyl alcohol) (PVA) is at 23–29°C. It is necessary to minimize the amount of water present during PVAc methanolysis. PVA samples produced under optimal conditions can be used as dispersants for the suspension polymerization of vinyl chloride.