TERMINATION PROCESSES IN GROUP TRANSFER POLYMERIZATION

Two major termination processes in the GTP of methacrylates and acryla tes have been studied. For methacrylates, intramolecular cyclization i s the dominant, if not sole, termination reaction. Both cyclization an d O/C-silyl isomerization of the chain end are observed for acrylates. Oligomerization experiments were used to study the relative rates of cyclization and propagation and the influence of temperature, catalyst and dp. Under typical GTP conditions for methacrylates, cyclization i s at least two orders of magnitude slower than monomer addition.