Green Polyurethane Adhesives for Wood Bonding
The Green polyurethane adhesive system was prepared using two types palm oil polyol having different molecular weight ~1100 (GA) and ~ 2200 (GB) respectively, 4-4-diphenylmethane diisocyanate (MDI) and nanoclay fillers via in-situ process. Adhesives were applied on both sides of two untreated wood substrate using brushing technique for lap shear test. The attached substrate then undergoes the curing process for 24 hours at room temperature with relative humidity of 50±5%. The disappearance of NCO peak in the Fourier transform infra-red (FTIR) spectrum showed that MDI has completely reacted to form PU. Contact angle measurement proved that high wetting condition obtains from green polyurethane (PU) adhesive. PU adhesive wood joint improved in shear strength with addition of 1wt% nanoclay for both green polyol.