Properties of polyurethane (PUR) films prepared from liquefied wood (LW) and ethylene glycol (EG)

Abstract

Abstract The wood of Cryptomeria japonica D. Don was liquefied in ethylene glycol (EG) with sulfuric acid (H2SO4) as a catalyst at 150°C for 60 min. The liquefied wood (LW)- and EG-based polyester polyols (EG-Polyest.-ol) were synthesized by reacting LW and EG with adipic acid (AA), respectively. Polyurethane (PUR) resins were made by mixing Polyest.-ol with isocyanate. The results show that LW-Polyest.-ol is a suitable raw material for PUR. The PUR films prepared with LW-Polyest.-ol have higher tensile strength with less elongation at breaking point than that with EG-Polyest.-ol. According to dynamic thermomechanical analysis, the PUR films prepared with EG-Polyest.-ol have a homogeneous molecular structure, whereas a phase separation has been found for those made with LW-Polyest.-ol. Thermal gravimetric analysis showed that the thermal degradation of LW-PUR films only starts at higher temperature than that of EG-PUR.