Synthesis and Characterization of Benzyl Methacrylate/Styrene Random Copolymers Prepared by NMP

BzMA/styrene random copolymers were synthesized in bulk (molar feed compositions f(BzMA,0)=10-90mol-%) at 90 degrees C by NMP with about 10% free SG1 relative to BlocBuilder initiator. Reactivity ratios (r(BzMA)=0.86+/-0.36, r(styrene)=0.27+/-0.14) were comparable to those reported by conventional radical polymerization. Linear (M)over-bar(n) increase with conversion was observed up to similar to 50% conversion, and all copolymers had (M)over-bar(w)/(M)over-bar(n) =1.2-1.4. The << k(p)><< K > (<< k(p)> =average propagation rate constant and << K >=average equilibrium constant) exponentially increased with increasing f(BzMA,0). Chain extensions with styrene at 110 degrees C initiated by B(z)MA/styrene copolymers made with f(BzMA,0) <80 mol-% were highly living while macroinitatiors with f(BzMA,0) >90 mol-% were not, based on GPC and P-31 NMR results.