Development of Polyurethane Wood Adhesives derived from Crude Glycerol based Polyols

Abstract. A type of polyurethane (PU) adhesives for wood bonding was synthesized from crude glycerol based bio-polyol by using a low cost, simple and efficient procedure. Effects of different variables including hydroxyl values, chain extenders, and molar ratio of –NCO/OH were investigated to determine a competitive formulation by determining lap shear strength and green strength of resultant adhesive joints. It was found that the resulting adhesives exhibited good performance, which could competitive with commercial PU adhesives in terms of lap shear strength and green strength. Chemical resistance of obtained PU adhesives to cold water, hot water, acid and alkali were evaluated with a result showing cold water making little influence in adhesion strength. The resulting PU adhesives, which were derived from crude glycerol based polyols, possessed promise advantages in wood adhesions.