A water-sensitive thermomechanical transition in a polyimide
Article first published online: 9 MAR 2003
Copyright © 1979 John Wiley & Sons, Inc.
Journal of Applied Polymer Science
Volume 23, Issue 4, pages 1189–1201, 15 February 1979
How to Cite
Ozari, Y., Chow, R. H. and Gillham, J. K. (1979), A water-sensitive thermomechanical transition in a polyimide. J. Appl. Polym. Sci., 23: 1189–1201. doi: 10.1002/app.1979.070230422
- Issue published online: 9 MAR 2003
- Article first published online: 9 MAR 2003
- Manuscript Revised: 10 FEB 1978
- Manuscript Received: 14 DEC 1976
The effect of water vapor on a polyimide has been investigated in the temperature region of −190 to 325°C using an automated torsion pendulum. A damping peak, T developes at −122°C (1 Hz) in the thermomechanical spectra of the polymer which is due to water–polymer interactions. The peak intensifies as the humidity of the conditioning atmosphere, at both 30° and at 325°C, increases and attains a limiting value at about 3000 ppmv H2O. The process is reversible. It is concluded that the number of sites in the polymer for interaction with water is low and limited (<0.3 molecule H2O per polymer repeat unit) and, assuming direct proportionality between the intensity of the loss peak and the amount of water adsorbed, that the adsorption of water vapor follows the Langmuir isotherm.