Self-repairing mechanism of polymer composite

Abstract

The self-repairing reaction of polymer chains cleaved due to degradation was elucidated through the use of degradation poly phenylene-ether (PPE) related polymer composites. In the case where the cleavage of main chain partially occurred, a spontaneous re-bonding reaction proceeded at the chain ends with copper/amine complex added as a catalyst. The relative value of molecular weight was determined as a criterion of the self-repairing reaction. This reaction was also found to proceed as a redox mechanism for supplying oxygen continuously into the system. Through these processes, the oxidation state of copper was changed from a mono-valent state of a di-valent state that was active for the re-combination reaction between chain ends in polymer. Moreover, blending several kinds of plasticizers with PPE enabled the increase of its molecular weight because of recombination between chain ends that had been cleaved by degradation. During the re-polymerization, water discharge was detected, and the correlation between the ratio of yielded water and increase of molecular weight was clarified. From these results, we concluded that the concept of the self-repairing mechanism could be applied to a wide range of industrial materials and that it had a strong potential to overcome environmental and resource problem in the near future.