Synthesis of PMMA and PMMA block copolymers at elevated temperatures by phosphor ylide-mediated polymerizations

The MMA polymerization initiated by (1‐naphthyl) triphenylphosphonium triphenylmethyl anion(TPM,NTPP) or the NTPP salt of the methylisobutyrate anion (MIB,NTPP) in THF at temperatures varying from 25 to 70°C appears to be a living polymerization as indicatred by a linear Mn vs. MMA conversion plot and by the narrow MW distributions. As indicated by the proton spectrum of MIB, NTPP in THF d8 the predominant polymerization intermediate appears to be the ylide formed exclusively by addition of the MIB anion to the 4‐carbon of the 1‐naphthyl group. This ylide shows upfield shifts for the 3‐proton of the cyclohexadienyl ring and of the 6‐ and 8‐protons of the remaining aromatic ring. The rates of the NTPP mediated polymerizations are reduced by factors of around 104‐105 compared to that mediated by the corresponding ylides formed by addition of MIB to the phenyl ring of tetraphenylphosphonium ion. The reductions in rate in the presence of NTPP make it possible to carry out MMA polymerizations under conditions not normally accessible.