INITIATOR-FREE PHOTOEMULSION POLYMERIZATION OF VINYL PROPIONATE AND ITS COPOLYMERIZATION WITH VINYL-ACETATE

Initiator-free photo-emulsion polymerization of vinyl propionate (VPr) and its copolymerization with vinyl acetate (VAc) were carried out in aqueous media at 0-degrees-C by using polyoxyethylene nonyl phenyl ether sodium sulfate as an emulsifier. In each case, poly(vinyl propionate) (PVPr) or the copolymer was obtained in a good yield. The average degree of polymerization (P(n)) of poly(vinyl alcohol) (PVA) obtained by saponification of PVPr was not high, and the ratios of isotactic triad (I), heterotactic triad (H), and syndiotactic triad (S) were 18.5, 49.6, and 31.6%, respectively. P(n)s of PVA's from the copolymers were higher than those from PVPr's, and the ratios of the tacticites of PVA's from the copolymers varied with varying feed monomer compositions.