Facile fabrication of degradable polyurethane thermosets with high mechanical strength and toughness via the cross-linking of triple boron–urethane bonds

Polyurethane thermosets with ultrahigh mechanical strength and toughness are fabricated by cross-linking isocyanate-terminated PU prepolymers with boric acids. The poly(boron-urethanes) can fully degrade into linear PU oligomers under acid solution.