Synthesis and properties of room-temperature self-healing polyurethane elastomers

Two kinds of polyurethane elastomers were synthesized. One containing acylhydrazone bonds was named TPIA. The other containing both acylhydrazone and disulfide bonds was named TPID. Self-repairable ability and reprocessability of these two elastomers were studied. The results show that: The polyurethane elastomer TPIA can automatically repair damage to it under acidic conditions. After self-healing for 24h, the strength and the elongation value at break recovered to 32% and 55% of the originality, respectively. The polyurethane elastomer TPID can automatically repair damage to it under visible light at room temperature. After 24h of self-healing time, 75% of the original strength and 100% of the original elongation values at break were obtained. These two polyurethane elastomers can be reprocessed in their cured state by just applying temperature and pressure.