The use of lignin from palm kernel shell (PKS) to fabricate oil palm mesocarp fiber (OPMF) particleboards

Abstract

Due to the abundance of oil palm waste in Thailand, PKS, being rich in lignin content, is a promising source of lignin while the cellulose rich in OPMF which suitable substitute for wood products in the manufacture of particleboard. The conditions used to extract lignin from PKS was investigated by Response Surface Methodology (RSM). The extracted lignin was then utilized as a substitute for phenol in the synthesis of phenol formaldehyde (PF) adhesive, with the aim of producing particleboard from a bio-based adhesive. The statistical results suggest that the highest crude lignin extraction was obtained when treating PKS under alkali condition at 155 °C for 214 min. The extracted lignin was characterized by FT-IR, 1H NMR, TG-DTA, and UV-Spectroscopy to assure the appearance of lignin. The so-produced lignin was then used as a phenol replacement in the formulation of an adhesive. It was found that bonding strength, via ASTM D5868-01, was improved with the addition of extract lignin from PKS, especially in the formulation of 100% substitution yielding the highest lap shear strength of 3.02 MPa. This adhesive was then applied in the manufacture of particleboards based on OPMF. The results suggest that partial substitution of phenol by lignin at 25% in the formation of particleboards had a modulus of rupture, modulus of elasticity, and thickness swelling comparable to PF adhesive.