Kinetic study of cyclopolymerization

Kinetic studies of cyclopolymerization have been reported in several papers to date, but the overall kinetics is not yet established. Therefore, divinylformal was synthesized and polymerized as a difunctional monomer, and the overall rate equation, Rp = k[I]3/4[M]3/2−2, was obtained. To interpret this irregular rate equation, elementary reactions were considered and the theoretical rate equation, Rp = k[I]1/2−1[M]2−1, was obtained. The overall activation energy of polymerization was 27.7 kcal./mole, and this value, together with the result of the measurement of residual unsaturation in the polymer, yielded a value for the difference of activation energy between cyclization and propagation reaction of 2.6 kcal./mole. The results of measurements of intrinsic viscosities and residual unsaturation in the polymer at various conversions suggest that the branching reaction occurs to some extent during polymerization. The polydivinylformal was hydrolyzed to poly(vinyl alcohol) with hydroxylamine hydrochloride, and the 1,2‐glycol structures in the poly(vinyl alcohol) were determined. The result showed a higher content of 1,2‐glycol structures than that in commercial poly(vinyl alcohol).