Improving Forest-Based Industrial Sustainability by Using Lignin-Phenol-Formaldehyde Adhesives

Abstract

Lignin is frequently obtained as byproduct from forest-based industries like pulp mills. Lignin can be used to replace phenol in the formulation of phenolic adhesive because its phenolic structures. Since its low reactivity, the phenolation method can be used to increase its usefulness for various purposes, among which lignin-phenol-formaldehyde resin synthesis. In this study, 30, 40 and 50 wt% of phenol were substituted with non-phenolated (LPF) and phenolated lignin (PLPF) to produce 6 adhesives. As references was used a commercial resin and a synthesized phenol-formaldehyde adhesive (PFA)without phenol substitution. The phenol content of kraft lignin was raised by 14.7% through the phenolation process. The characteristics of the adhesives, for both LPF and PLPF, were modify using lignin. The adhesive replacing phenol with 50% of phenolated lignin was considered the best resin due to higher percentage of replacement, improved adhesive performance regarding plywood strength property and gel time.

Keywords: kraft lignin, adhesives for wood, phenolic