ISSN:
0360-6376
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The reaction of a polyether-based polyurethane foam with dry atmospheric pressure steam was examined as one approach to waste polyurethane foam recovery. Complete reaction at temperatures between 190 and 230°C yielded high-quality polyol, isomeric toluenediamines, and carbon dioxide as primary products. Kinetic analysis of toluenediamine yields versus time suggested the occurrence of a parallel first-order reaction scheme wherein urethane linkages react up to 50 times faster than urea linkages. The results derived from kinetic experiments and ancillary thermochemical and spectroscopic studies indicated that urethane linkages are broken by direct hydrolysis, whereas urea linkages undergo thermal dissociation to parent isocyanate and amine. Subsequent rapid hydrolysis of the isocyanate produced was necessary to obtain high yields of toluenediamine products. The rate of the slower reaction, dissociation of urea linkages, can be enhanced by a factor of 20 by the addition of trace amounts of sodium hydroxide to the foam.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1980.170180215
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