Cocondensation of NaOH-catalyzed liquefied wood wastes, phenol, and formaldehyde for the production of resol-type adhesives

Abstract

In this study, wood (Betula maximowiczina Regel) wastes were liquefied with phenol in the presence of NaOH at an elevated temperature of 250 °C. The liquefied wood was then resinified with formaldehyde, and the resulting resol-type resin adhesives were applied for the production of plywood. The results indicated that almost all of the resol-type resin adhesives prepared met the Japanese Industrial Standard as far as dry shear adhesive strengths of plywoods were concerned. Furthermore, boiling water-resistant resol-type adhesives could be prepared from the resinification of NaOH-catalyzed liquefied wood with formaldehyde at a formaldehyde/phenol ratio of at least 2.0 and from the addition of an appropriate cross-linking agent such as polymeric diphenylmethane diisocyanate to the resol.