A Study of the Solvent Effect on the Polymerization of N-Phenylethyleneimine

Abstract

Abstract The effect of solvents on the cationic polymerization of N-phenylethyleneimine with formic acid catalyst has been studied quantitatively. The polymerization rates in the various solvents used increase in the following order: diethyl ether\simeqtetrahydrofuran<toluene\simeqcarbon tetrachloride<anisole<methyl acetate<ethylene dichloride<N,N-dimethylacetamide<dimethyl sulfoxide<epichlorohydrin<acetonitrile. In polar solvents with high dielectric constants, the rates are much larger than those in nonpolar solvents with low dielectric constants. However, in the solvents with similar dielectric constants, such as acetonitrile and N,N-dimethylacetarnide, ethylene dichloride, methyl acetate and tetrahydrofuran, and anisole and diethyl ether, the rates decreased with an increase in the nucleophilicity of the solvents, and the dependence of the polymerization rate on the nucleophilicity of the solvents is much larger in polar solvents than in nonpolar solvents. The propagation rate was markedly influenced by the nature of the solvent, whereas the initiation rate was only a little influenced.