Highly efficient block copolymerization of methyl and t-butyl methacrylates by an incomplete and slow initiation system

Abstract

Block copolymerization of methyl methacrylate (MMA) with t-butyl methacrylate (t-BMA) was carried out in toluene at-78°C with triphenylphosphine (Ph3P)-triethylaluminum (Et3Al) initiating system. Polymerization of MMA with Ph3P-Et3Al under the same conditions gave highly syndiotactic PMMA living anion with low initiator efficiency. Even though a large part of the initiator remained unreacted, polymerization of t-BMA with the living anion of PMMA gave block copolymer without formation of poly(t-BMA), since t-BMA alone could not be polymerized under the same conditions due to the inability of initiation with Ph3P-Et3Al.