Effect of ethyl aluminium sesquichloride on the specificity of the reactions of 1-methyl-1-methoxycarbonylethyl radical - Implications as to the mechanism of alternating copolymerization

Abstract

Copolymerizations of styrene and methyl methacrylate (MMA) have been carried out with azo-bis-(methyl isobutyrate-α-13C) (AIBMe-α-13C) as initiator and in the presence of ethyl aluminium sesquichloride (EASC). The specificity of the 1-methyl-1-(methoxycarbonyl)ethyl radical (I) for reaction with styrene over MMA is substantially enhanced by the presence of very low concentrations of EASC. This behaviour is consistent with the involvement of a complexes radical and suggests that such species may play an important role in Lewis acid induced alternating copolymerization. © 1992 Springer-Verlag.