Polymerization mechanism in methyl methacrylate - Grignard reagent system. I. Phenylmagnesium bromide

Abstract

The mechanism of stereospecific polymerization in a methyl methacrylate-Grignard reagent (C6H5MgBr) system is studied as a function of polymerization temperature with high-resolution nuclear magnetic resonance (NMR) spectroscopy for obtained polymers. It is found that the maximum temperature during the reaction in our experiments is appropriate for adoption as the polymerization temperature rather than the commonly used setting temperature. As a result it is found that the mechanism is different at temperatures higher and lower than about 266°K. Also, the NMR spectra of C6H5MgBr in a deuterated toluened8 are measured over a wide range of temperatures and remarkable change is observed in the vicinity of about 266°K. It may reflect the above difference in polymerization mechanisms on both sides of about 266°K.