Abstract
Since the methyl group of the acetyl radical is the principal site in the branching of polyvinyl acetate, polyvinyl alcohol (PVA) obtained by saponification has carboxyl group as the end group.In the present report the determination of carboxyl group in PVA was studied by polarography. After treating PVA with calcium acetate, calcium combined with PVA was determined polarographically by the use of 4-6N ammonium hydroxide solution composed of Zn-Complexonate as the supporting electrolyte.The carboxyl groups of PVA obtained by the bulk and solution polymerizations were measured by this method.From these results, the transfer constant with the monomer and that with the polymer of vinyl acetate were obtained. The former was 2.6×10-4, and the latter 1.4×10-4, (at 60°C).
