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

In this study, wood (Betula maximowiczina Regel) wastes were liquefied with phenol in the presence of NaOH at an elevated temperature of 250 degreesC. 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.