Self-healing of thermoplastics via reversible addition-fragmentation chain transfer polymerization

To prepare self-healing thermoplastic composites, techniques of living polymerization and microencapsulation were employed. The matrix was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, in which encapsulated monomer was dispersed. Upon mechanical damage of the composites, the monomer released from broken microcapsules resumed polymerization with the living matrix, establishing chemical bonding between the cracked planes. As a result, full recovery of mechanical strength was achieved at room temperature without manual intervention. Compared to the self-healing material made by atom transfer radical polymerization (ATRP) in the authors' previous work, the present one possesses more meaningful applicability owing to the versatility and robustness of RAFT polymerization.