Polyol recovery from biomass‐based polyurethane foam by glycolysis

Abstract

Abstract Biomass‐based polyurethane foams (PUFs) were degraded by glycolysis and the polyols recovered were reused to prepare a rigid polyurethane foam. Biomass‐based PUFs were prepared from liquefied wood or starch polyols and grafted products with polycaprolactone. The glycolysis was conducted using diethylene glycol (DEG) as a solvent and potassium acetate as a catalyst under various reaction conditions. The effects of reaction conditions on the properties of the polyols recovered were examined. The average‐weight molecular weight (Mw) and viscosity decreased as the reaction time, temperature, and ratio of DEG/PUF increased, whereas the hydroxyl value increased. It was found from IR measurements that the conversion of the urethane functional group (NCOO) increased as the glycolysis proceeded. The PUF prepared from the recovered polyols had properties comparable to those of the raw PUF used in glycolysis. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 975–980, 2005