Polyvinyl Esters of Omega-H-Perfluoroacids and Polyvinyl Alcohol Obtained from Them,
FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
Pagination or Media Count:
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 gcc. 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 916cm. This is characteristic for a syndiotactic structure.
- Organic Chemistry