UTILIZATION OF LIGNIN MODIFIED BY BROWN-ROT FUNGI .1. PROPERTIES OF FLAKEBOARD PRODUCED WITH A BROWN-ROTTED LIGNIN MODIFIED PHENOLIC ADHESIVE

Data on an adhesive system for flakeboard is presented in which 35% of the phenol in a phenolformaldehyde (PF) resin is replaced with brown-rotted lignin (BRL).This BRL, which has previously been shown to be rich in phenolic hydroxy! groups, has a higher formaldehyde reactivity than a purified Kraft lignin. Formulation characteristics and molecular weight of the BRL-PFresin were determined and compared with a control PF resin. The physical properties of flakeboard including internal bond (IB), dry static bending (modulus of rupture, MOR), accelerated aging MOR, water absorption and thickness swelling were examined and found to be comparable for both adhesivcs.The results of this study demonstrate that BRL can be used as a partial substitute for phenol in structural wood adhesives. © 1990, Walter de Gruyter. All rights reserved.