“…Research Institute for Atomic Energy, Osaka City University, Sugimoto-cho, Sumiyoshi-ku, Osaka, Japan. Received April 3,1974 ABSTRACT: It was found, surprisingly, that sodium thiophenoxide initiates the polymerization of styrene in polar aprotic solvents such as M-Y'-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and hexamethylphosphoramide (HMPA). It initiated nearly no polymerization in less polar solvents such as benzene, toluene, dioxane, dimethoxyethane, and tetrahydrofuran.…”