Process for converting the decomposition products of polyurethane and

Abstract

Decomposing polyurethane foams and converting the depolymerized reaction product containing amines, both aromatic and aliphatic, into polyols suitable for reaction with polyisocyanate to produce fresh polyurethane foam, by first reacting polyurethane foam with ammonia or an amine such as diethylene triamine or ethanolamine, or with a polyol such as polypropylene glycol, and reacting the resulting decomposition product containing a mixture of polyols, ureas, and amines, which can include primary and secondary amines, with an alkylene oxide such as ethylene oxide or propylene oxide, at elevated temperature, preferably about 120.degree. to about 140.degree. C., in an autoclave under autogenous pressure, to convert such amines to polyols. The resulting reaction mixture containing polyol fragments from the decomposition of the polyurethane, and additional polyols from the reaction with alkylene oxide can be incorporated with fresh polyurethane reactants, including polyisocyanate, or additional polyol and polyisocyanate, thus permitting efficient recovery and re-use of otherwise useless scrap polyurethane materials.