Studies on the polymerization of bifunctional monomers. XV. Anionic polymerization of o‐divinlbenzene

Anionic polymerization of o ‐divinylbenzene was carried out with organolithium and alkalimetal‐naphthalene catalysts. The extent of cyclization in polymer was generally smaller than in cationic polymerization. The influence of the counter cation and of the solvent on the cyclization constant, r c , observed in polymerization with alkalimetal‐naphthalene catalysts agreed qualitatively with that on the rate of anionic propagation of styrene in the same system, if r c was considered to increase with the reactivity of the uncyclized anion. In the sodium naphthalene/THF system, r c decreased on addition of NaBPh 4 and this result was considered to indicate the free‐anion propagation. In the same system, the apparent difference in activation energy between intramolecular cyclization and intermolecular propagation was 2–3 kcal·mole −1 .