Preparation of Polyurethane Adhesive from Wood Sawdust polyol: Application of Response Surface Methodology for Optimization of Catalyst and Glycerol

Abstract

Response surface methodology (RSM) was applied to optimize catalyst and glycerol values as suitable additives in polyurethane adhesive production and determine the appropriate gel time. Polyurethane adhesive was prepared using polyol, two types of diisocyanate (PMDI and TDI), catalyst, and glycerol with equal NCO/OH ratio. Polyol was produced using the liquefaction process of Beechwood sawdust with ethylene carbonate solvent at 130°C for 120 minutes under atmospheric pressure. Fourier transform infrared spectroscopy (FTIR) results revealed the existence of the hydroxyl groups in the liquefied wood and confirmed that the liquefied wood sawdust is a source of polyols and a potential chemical stock for the synthesis of polyurethane. Also, the adhesive bonding strength was evaluated by lap shear strength. The result of optimization by response surface methodology showed that catalyst and glycerol values were 0.11% and 1.56% for PU adhesive with PMDI, and catalyst and glycerol values of 0.34% and 3.12%for PU adhesive with TDI were appropriate.