Recent progress in enzymatic degradation and recycling of polyurethanes

Abstract

The widespread production of polymeric materials has precipitated severe environmental challenges, prompting a pressing need for effective solutions. Among these materials, polyurethanes (PUs) stand out significantly due to their versatility in synthetic approaches, manufacturing, properties, and applications. This versatility has led to a high demand for PUs, resulting in significant waste accumulation at the end of their lifecycle. Along with that, the PU's inherent chemical stability prevents the occurrence of natural hydrolytic processes. Consequently, there is a critical need for sustainable recycling methods, particularly those capable of recovering reusable monomers. Recycling is a leading way to manage waste by reducing plastic pollution and its environmental impact, which can be performed through mechanical, chemical, and biological processes. Biological degradation occurs through the action of enzymes and microbes that can potentially convert the polymers into monomers or other valuable chemicals. This approach presents an opportunity to establish a sustainable and circular economy within the PUs industry while considerably reducing the environmental impact. This review highlights enzymatic degradation as a promising solution for PU recycling by discussing the types of enzymes utilized in the process, potential biochemical pathways for PU degradation, recent achievements, and future remarks for this process.