On leave from Instytut Włókien Sztucznych, Politechnika Łódzka, Poland.
Hydrolytic degradation of cured urea–formaldehyde resin†
Article first published online: 9 MAR 2003
Copyright © 1983 John Wiley & Sons, Inc.
Journal of Applied Polymer Science
Volume 28, Issue 11, pages 3313–3320, November 1983
How to Cite
Dutkiewicz, J. (1983), Hydrolytic degradation of cured urea–formaldehyde resin. J. Appl. Polym. Sci., 28: 3313–3320. doi: 10.1002/app.1983.070281101
Corrected proofs received September 12, 1983
- Issue published online: 9 MAR 2003
- Article first published online: 9 MAR 2003
- Manuscript Accepted: 12 APR 1983
- Manuscript Received: 13 DEC 1982
The degradation of cured urea–formaldehyde (UF) resin in aqueous suspension was investigated by gravimetric analysis of the changes in the content of nonextractable low-molecular components. In acid conditions (pH 4.0) at 47°C the consecutive processes of post-curing and of polymer break-down (activation energy 90 kJ/mol) are detectable whereas at 80°C and 97°C only the formation of the extractable hydrolysates is observed. The degraded polymer contains less carbonyl groups than does the original resin substrate as shown by means of infrared (IR) analysis. In contrast to the results of the tests carried out in acid conditions, in neutral and basic aqueous media the hydrolytic decomposition of UF macromolecular network is less significant. During the hydrolysis of UF polymer at 30°C–45°C the concentration of formaldehyde released from the resin to the aqueous phase increases initially (2 days) at a relatively high rate both at acid and alkaline pH. Then its growth slows down but is still detectable in acid conditions, whereas in basic medium no further liberation of HCHO is observed.