Termination processes in group transfer polymerization

Two major termination processes in the GTP of methacrylates and acrylates have been studied. For methacrylates, intramolecular cyclization is the dominant, if not sole, termination reaction. Both cyclization and 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 is at least two orders of magnitude slower than monomer addition.