Extremely Strong and Tough Biodegradable Poly(urethane) Elastomers with Unprecedented Crack Tolerance via Hierarchical Hydrogen-Bonding Interactions

The elastomers with the combination of high strength and high toughness have always been intensively pursued due to their diverse applications. Biomedical applications frequently require elastomers with biodegradability and biocompatibility properties. It remains a great challenge to prepare the biodegradable elastomers with extremely robust mechanical properties for in vivo use. In this report, we present a polyurethane elastomer with unprecedented mechanical properties for the in vivo application as hernia patches, which was obtained by the solvent-free reaction of polycaprolactone (PCL) and isophorone diisocyanate (IPDI) with N,N-bis(2-hydroxyethyl)oxamide (BHO) as the chain extender. Abundant and hierarchical hydrogen-bonding interactions inside the elastomers hinder the crystallization of PCL segments and facilitate the formation of uniformly distributed hard phase microdomains, which miraculously realize the extremely high strength and toughness with the fracture strength of 92.2 MPa and true stress of 1.9 GPa, while maintaining the elongation-at-break of approximate to 1900% and ultrahigh toughness of 480.2 MJ m(-3) with the unprecedented fracture energy of 322.2 kJ m(-2). Hernia patches made from the elastomer via 3D printing technology exhibit outstanding mechanical properties, biocompatibility, and biodegradability. The robust and biodegradable elastomers demonstrate considerable potentials for in vivo applications.

Automated summary

This study presents a polyurethane elastomer with unprecedented mechanical properties for in vivo application as hernia patches. The elastomer, obtained by solvent-free reaction, exhibits extremely high strength and toughness. Abundant and hierarchical hydrogen-bonding interactions hinder crystallization and promote the formation of uniformly distributed hard phase microdomains, resulting in high fracture strength, true stress, elongation-at-break, and fracture energy. 3D printed hernia patches made from this elastomer show outstanding mechanical properties, biocompatibility, and biodegradability. These robust and biodegradable elastomers have great potential for in vivo applications.