Living diradical polymerization

A diradical initiator containing two thermoreversible bonds was prepared and used for the polymerization of styrene at 90°C. The monomer consumption and the variation of the molecular weight were monitored with time. The results show that the process can be considered as living and that the polymerization rate is independent of the radical initiator concentration. By elemental analysis of the chain ends it was concluded that the propagation reaction occurs at both ends.