Tacticity dependence of reactivity of stereoregular poly(methyl methacrylate) macromonomers having a methacryloyl function in radical polymerization

Abstract

Radical polymerizations of highly isotactic (it-) and highly syndiotactic (st-) poly(methyl methacrylate) (PMMA) macromonomers having a methacryloyl function were studied in benzene-d 6 at 60°C with 2,2′-azobisisobutyronitrile (AIBN). Rate of polymerization (R p) was determined from the consumption of the macromonomer by means of 1H NMR spectroscopy. The R p of the it-PMMA macromonomer was larger than that of the st-PMMA macromonomer. Concentrations of propagating radicals, [M·] , were estimated for the polymerization with di-t-butyl peroxide in benzene under irradiation of light at 30°C. The value of [M · ] for the polymerization of the st-PMMA macromonomer was larger than that for the polymerization of the it-PMMA macromonomer. The results indicated that rate constant of propagation (k p) for the it-PMMA macromonomer was larger than that for the st-PMMA macromonomer.