Methanolysis investigation of a model polyurethane (PUR), poly[ethylene=methylene bis(4-phenyicarbamate)], and the commercially available PUR foam, Sofran((R)) is reported. The methanolysis conditions were in the temperature range from 160 to 300 degreesC and at pressures up to 15 MPa, partly in the supercritical state of methanol. For both the PURs the decomposition percentages are over 90% at temperatures above 200 degreesC. Methyl carbamate was formed in the reaction mixtures by the decomposition at all temperatures studied. With the GC measurement of the carbamate, it is revealed to be decomposed into methanol and 4,4'-methylenediphenyl diisocyanate (MDI). The decomposition temperature of the carbamate was determined to be 250 degreesC by TG-DTA measurement. The chemical recycling process flow on PUR compounds is proposed. (C) 2004 Elsevier Ltd. All rights reserved.
