Bio-based, self-healing, shape memory, UV-shielding and recyclable polyurethane elastomers by Epigallocatechin-3-gallate (EGCG) and polycaprolactone

In light of the gradual exhaustion of conventional fossil fuels, renewable materials are becoming increasingly important. Developing biobased polyurethanes (PU) elastomers with self-healing, recyclability and good mechanical property has received considerable attention. By using an epigallocatechin gallate (EGCG) and Polycaprolactone triol (PCL) based on phenol-carbamate bonds and hydrogen bonds, a series of PU (PCIEGCG-X) elastomers were synthesized, which resulted in excellent tensile strength (11.53 MPa), self-healing properties (98 %), and excellent recyclability without any apparent reduction in tensile strength. Additionally, the PU elastomer was also shown to exhibit good shape memory effect with a shape fixation rate above 85.41 % under room temperature, and a higher shape recovery rate exceeding 93.92 %. Self-healing PU elastomers allowed repeated healing cycles to be carried out at 50°C without requiring external force. Aside from exhibiting excellent antibacterial properties, the prepared PU elastomers also displayed excellent free radical scavenging abilities, UV absorption abilities, and biocompatibility as a result of catechins. These features make bio-based PU elastomers attractive for applications such as temperature sensors and biological applications. [Display omitted] •A polyurethane (PU) elastomer was synthesized through renewable bio-based catechins.•The PU exhibited excellent self-healing, shape memory, and recyclable properties.•The PU elastomer possessed ultra-UV-blocking and antibacterial capabilities.•The PU elastomer exhibited excellent shape memory assisted self-healing property.