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 in-creased, 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. (C) 2004 Wiley Periodicals, Inc.