Non-isocyanate polyurethane foams: where we stand and what comes next?

Abstract

Polyurethane foam stakeholders are currently facing stringent regulatory constraints, such as the REACH regulation restricting the use of isocyanates and increasing environmental pressures calling for more sustainable materials. This dual challenge compels both academia and industry to innovate and redesign conventional PU chemistry and foaming toward non-isocyanate solutions while integrating eco-design principles to enhance recyclability and circularity. This tutorial review summarizes the current advances in synthetic strategies for producing non-isocyanate polyurethanes (NIPUs), with a particular focus on foaming concepts, which have witnessed a significant acceleration in development over the last five years. Emerging end-of-life management solutions via chemolysis or physical means – exploiting covalent adaptable network features – and applications of NIPU foams are also discussed. For each aspect, a comparative analysis between conventional PU and NIPU highlights the remaining technological, environmental and economic challenges that must be addressed to achieve competitive, scalable, and sustainable NIPU foams.