Adhesives from waste paper by means of phenolation

Recently the effective use of woody materials has been of interest from the viewpoint of forestry preservation. Newsprint is one of the most abundant of woody materials which are discarded into the environ-ment after use. They would be, however, easily recovered from the market. The application of phenolation to cellulosic materials is one possibility for the utilization of waste papers. Phenolation is a newly-established method by which lignocellulosic materials are completely converted to substances soluble in some polar organic solvents. Waste newsprint is subjected to phenolation in the presence of an acidic catalyst. The phenolated product was then methylolated in order to prepare alkaline curable adheisve resins. The chemical characteristics of the phenolated products were studied and the properties of plywood adhesives from them were evaluated. The results indicated that cellulose decomposed and reacted with phenol, producing complicated compound having a phenolic moiety during phenolation and that the compound reacted with formaldehyde, leading to resinous substance which could be thermoset. The adhesives from the resins of phenolated newsprint provided comparable properties to a commercial phenolic resin in cure behavior, resin viscosity and tensile bond strength. The products of cellulose phenolation, therefore, are expected to be a source of wood adhesives comparable with phenolic resins.