Chemical Structure Design of Heat-Resistant Polyurethane Adhesives

摘要

This paper describes the chemical compositions of heat-resistant polyurethane adhesives that are composed of the reaction products of a poly (methylene diphenyl diisocyanate), a polyol, and a hydroxyl phenol. Resorcinol or its isomer (catechol or hydroquinone) is reacted into the polyurethane chains to increase heat-resistance of the polymeric structures. In addition, a phosphorous-containing polyol can be used as a reactive component to provide fire-retardant property. The aromaticity introduced by the hydroxyl phenol forms the basis of a heat-resistant polyurethane adhesive suitable for applications in the manufacture of wood products. The heat resistance is a result of incorporating thermally stable hydroxyl phenol molecules into the polymeric structures of the wood adhesive system. This adhesive system is fast moisture-curable at ambient temperature and has shown a substantial improvement over the heat performance of commercial polyurethane wood adhesives. This novel wood adhesive system also possesses high water-resistance, making it suitable for the manufacture of highly durable engineered wood products.