Polyvinyl Esters of Omega-H-Perfluoroacids and Polyvinyl Alcohol Obtained from Them

摘要

By means of radical polymerization at 20 we obtained polyvinyl esters of omega-H-perfluoroacids from monomers. The product of their saponification - polyvinyl alcohol (PVA) - differs significantly from PVA which is obtained by other methods (mainly with respect to its exceptionally high water resistance). It contains 0-0.25% glycol groups (based on oxidation of periodic acid). When heated higher than the glass transition temperature Tc = 90 it is crystallized rapidly, and it has a melting point Tn = 236 (determined dilatometrically) and increased density d20 = 1.315 g/cc. There are no cross bonds in PVA; a melt of it is fluid. PVA dissolved only at a temperature higher than 150 (under pressure). In the IR spectra of PVA a band of absorption of increased intensity was detected at 916/cm. This is characteristic for a syndiotactic structure.