Kinetics of the polymerization of divinylbenzene isomers

The overall rates of polymerization of m‐ and p‐divinylbenzene, a 2:1 mixture of the meta and para isomers, and commercial divinylbenzene have been followed viscometrically. Data at 60 and 80°C. show that the meta isomer polymerizes most rapidly. Ratios of rates show differences in activation energies. An effect on the overall rates is tentatively attributed to the increased resonance stabilization of the p‐vinylphenyl‐derived radical which further decreases the already low reactivity of the styrene‐derived radical. The possibility that steric factors contribute significantly to the rate difference is considered to be unlikely.