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  = 10–90 mol‐%) at 90 °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 $\overline M _{\rm n} $ increase with conversion was observed up to ∼50% conversion, and all copolymers had low $\overline M _{\rm w} /\overline M _{\rm n} $  = 1.2–1.4. The $\left\langle {k_{\rm p} } \right\rangle \left\langle K \right\rangle $ ( $\left\langle {k_{\rm p} } \right\rangle $  = average propagation rate constant and $\left\langle K \right\rangle $  = average equilibrium constant) exponentially increased with increasing f BzMA,0 . Chain extensions with styrene at 110 °C initiated by BzMA/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 31 P NMR results.