Synthesis and Properties of Crosslinked Gels of Vinyl Alcohol-Allyl Alcohol Copolymer

Abstract

Three kinds of gel beads of crosslinked vinyl alcoho-allyl alcohol copolymer were prepared, The frst gel was prepared by partial saponication of vinyl acetate-diallyl phthalate copolymer, that has been obtained by suspension polymerizaton. The excluded molecular weight increased with increasing the degree of saponication, and, its maximum value was about 52000. The second gel was prepared by crosslinking of vinyl alcohol-allyl alchool copolymer, that was obtained by perfectsaponi cation of vinyl acetate-diallyl phthalate copolymer, with epichlorohydrin. Its maximum value of the excluded molecular weght was about 100000. The third gel was prepared by hydrolysis of vinyl aceetate-diallyl phthalate copolymer, which was polymerized in the presence of adiluent, and subsequent cross In king With epichlorohydrin. In this case; cyclohexane was used as a diluent, which serves as a solvent fr vinyl acetate and diallyl phthalate and desnt dessolve the polymer The gel obtained was highly'porbus. The excluded molecular weight the gels increased with increasing volume of an, added diluent during polymer ization and its maximum excluded molecular weight was about 200000. It was shown that a series of gels of different degrees of crossIinking could be obtained by controlling saponi-catino of vlnyl acetate-diallylphthalate copolymer and the excluded molecular weight of the gel was larger than that of apoly(vinyl alcoho1)gel.