Methylene diphenyl isocyanate (MDI) -based polyurethane flexible foams were decomposed by alkanolamines without a catalyst at 150-degrees-C. The decomposition products were completely separated into two layers. The upper liquid layer was a polyether polyol, and the lower liquid layer was methylene diphenyl amine (MDA) and alkanolamine derivatives. These layers were analyzed using gel permeation chromatography (GPC) and C-13-NMR. The upper layer was obtained as a relatively pure polyether. The lower layer was observed to be MDA and 2-hydroxyethyl carbamic acid ester prepared from alcoholysis products during the decomposition reaction. It was thought that the decomposition process of polyurethane foam by alkanolamines was not aminolysis but alcoholysis. co 1994 John Wiley & Sons, Inc.