Stereospecifity in radical polymerization of methyl α-(chloromethyl)acrylate

Poly(methyl alpha-(chloromethyl)acrylate)s (PMCMAs) obtained by homopolymerizations of methyl alpha-(chloromethyl)acrylate (MCMA) in benzene at different temperatures were converted to poly(methyl methacrylate)s (PMMAs) by reduction with tributyltin hydride. The reduction proceeded smoothly to yield PMMA exhibiting no H-1 NMR resonance due to the CH2Cl group. The tacticity of the PMCMA obtained at 40 degreesC was determined using the H-1 NMR resonances of the alpha-methyl group of PMMA derived: mm/mr/rr = 8/56/36. Apparently, the propagation of MCMA preferred r addition to a lower extent in comparison with that of MMA. The more polar and the bulkier alpha-substituent ClCH2 (relative to CH3) would diminish the effect of the carbomethoxy group, thus resulting in a lower level of synditacticity than in MMA polymerization. The tacticity of MMA-MCMA copolymers estimated after conversion to PMMA varied from that of PMMA to that of PMCMA; an increase in MCMA content in the feed resulted in a decrease in rr content. Coisotactic parameters for copolymerization of MCMA with MMA-d(8) were determined according to Hatada's procedure for determination of these parameters [Polym J 19 (1987) 1105]. (C) 2003 Elsevier Science Ltd. All rights reserved.