Fast Recycling of Polyurethane Foams Containing Bio-based Ester-Cleavable Segments

Abstract

Polyurethane (PUR) foams, the most widely produced thermosets globally, have become a major contributor to the issue of huge plastic waste overflow. Currently, most PUR waste is managed through conventional methods like landfilling and incineration. However, to adhere to a circular economy, it is crucial to consider a new strategy that begins with the design of PUR foams, ensuring they are easier to recycle. In order to reach this target, the bio-based succinic acid-polyol with cleavable ester linkages was incorporated into the structure of PUR foams. The fabricated semi-rigid PUR foams readily undergo glycolysis, yielding a recycled polyol suitable for the preparation of the bio-based rigid PUR foams. Up to 50 wt% of the virgin polyol can be replaced by its recycled alternative, producing stable foams with satisfactory mechanical properties, highly closed cellular structure and improved thermo-insulating properties. This study, therefore, marks a pivotal advancement in developing new PUR materials that adhere to circular economy principles, incorporate sustainable inputs, and facilitate easier recycling at the end of their lifecycle.