General Purpose Adhesives Prepared from Chemically Decomposed Waste Rigid Polyurethane Foams

Abstract

Waste rigid polyurethane foams were decomposed by glycolysis. IR and GPC analyses showed that the decomposed products contained large amounts of reactive polyurethane oligomers. Increases of the ratio of monoethanolamine to diethyleneglycol, of reaction temperature, and of reaction time increased the hydroxyl value and amine value of the reaction products, as well as lowering their viscosity. The decomposed products were examined as to suitability to be used directly as hardeners for epoxy adhesives. Studies included curing condition, the ratio of the decomposed products to epoxy resin, and their combined use with the amine hardener or additive, which is being used in the conventional epoxy adhesive systems. The use of the decomposed products from waste rigid polyurethane foam for epoxy adhesives improved the bonding or shear strength of the adhesive systems. This method also has economic advantage, because it does not need any complicated after-treatment of the decomposition reaction products. © 1993, The Society of Polymer Science, Japan. All rights reserved.