Reaction variables and a proposed mechanism of open-pore urea/formaldehyde structure formation
Article first published online: 9 MAR 2003
Copyright © 1979 John Wiley & Sons, Inc.
Journal of Applied Polymer Science
Volume 23, Issue 2, pages 381–391, 15 January 1979
How to Cite
Salyer, I. O. and Usmani, A. M. (1979), Reaction variables and a proposed mechanism of open-pore urea/formaldehyde structure formation. J. Appl. Polym. Sci., 23: 381–391. doi: 10.1002/app.1979.070230208
- Issue published online: 9 MAR 2003
- Article first published online: 9 MAR 2003
- Manuscript Revised: 3 NOV 1977
- Manuscript Received: 17 JUN 1977
Formation of open-pore urea/formaldehyde structures from nonetherified urea/formaldehyde resins involves reaction of one or more methylol groups with other methylol or amino groups. The structure formation proceeds through particle formation and growth until all the resin is consumed. A strong acid is preferred for achieving a porous structure in urea/formaldehyde resins; weakly ionized acids produce structures with low yield. Colloidal instability is an asset in porous structure formation. An 80:20 polyethylene oxide/polypropylene oxide block copolymer of approximate molecular weight 8500 has been found to be an entropic-type destabilizer in the formation of porous structures.