Self-healing linear polymers based on RAFT polymerization

Self-healing polystyrene (PS) composites were fabricated, in which glycidyl methacrylate (GMA)-loaded microcapsules were embedded. Because the matrix PS was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, it kept living characteristics and was able to resume the polymerization so long as monomers were available. Upon damage of the composites, the GMA released from the broken capsules infiltrated into the cracks and was copolymerized with the matrix PS according to the above mechanism. As a result, the cracked planes were covalently re-bonded, offering recovery of impact strength. Compared to the self-healing system based on atom transfer radical polymerization (ATRP), which is also an approach of living polymerization, the current one possesses robust vitality in air and eliminates the possibility of acceleration of matrix degradation aroused by metal ions. Additionally, the resultant self-healing PS composites have an advantage in coloration, which is important for satisfying esthetic requirement in practice.