Polymerization behavior of a homotrienes, 1,1-diethoxy carbonyl-2-(1,3butadienyl) cyclopropane(BCP),1,1-diethoxycarbony1-2-(1-methyl-1,3-butadienyl) cyclopropane[(1-Me)-BCP], 1,1-diethoxycarbonyl-2-(3-methyl-1,3-butadienyl)cyclopropane [(3-Me)-BCP], 1,1-diethoxy-carbonyl-2-(1,3-dimethyl-1,3butadienyl)cyclopropane [(1,3-DMe)-BCP] were investigated. They were prepared from 1,1-diethoxycarbonyl-2-formylcyclopropane or 1,1diethoxycarbonyl-2-acethylcyclopropane with triphenyl phosphine allyl bromide or methallyl chloride salt by Wittig reaction.
Butadienylcyclopropane derivatives could polymerize in 1,2-, 1,4-, 5,7-, or 1,7-fashion. BCP was highly polymerizable and spontaneous polymerization occurred slowly on standing at room temperature. Most of polymers were cross-linked in bulk polymerization, but in solution polymerization, 1,2type or 1,4-type polymer were concurrent. (1-Me)-BCP polymerized in 1,2fashion in bulk or solution polymerization. The bulk polymerization of (3Me)-BCP was obtained 58% of 1,2-type and 42% of 1,4-type polymer. To investigate the possibility of 1,7-polymerization,(1,3-DMe)-BCP was synthesized. But the polymerizability of (1,3-DMe)-BCP was very low. The results indicates that the polymerization proceeded via butadienyl type pathway, and the polymerizability of this monomer decreased with more methyl substituents.
