Influence of polycaprolactam morphology on thermal cis–trans isomerization and photofading of azo dyes differently dispersed in it: A kinetic study
Article first published online: 10 MAR 2003
Copyright © 1990 John Wiley & Sons, Inc.
Journal of Applied Polymer Science
Volume 41, Issue 3-4, pages 765–773, 1990
How to Cite
Dubini-Paglia, E., Beltrame, P. L., Marcandalli, B. and Seves, A. (1990), Influence of polycaprolactam morphology on thermal cis–trans isomerization and photofading of azo dyes differently dispersed in it: A kinetic study. J. Appl. Polym. Sci., 41: 765–773. doi: 10.1002/app.1990.070410323
- Issue published online: 10 MAR 2003
- Article first published online: 10 MAR 2003
- Manuscript Accepted: 21 JUN 1989
- Manuscript Received: 27 JAN 1989
Two polycaprolactam films were prepared characterized by different crystallinity degrees, the free volume model being prevalent in the former and the pore model in the latter. They were colored with azo dyes XC6H4NNC6H4N(C2H5)2 (where X is H and COOH), the latter of which gives specific interactions with the polymer. The kinetics of the thermal cis–trans isomerization of these dyes has been studied below and above the glass transition temperature of the polymer (Tg) in the range 20–80°C. In every case, the isomerization process was found to be the result of a multiplicity of first-order reactions and the dependence on temperature exhibited a break at the Tg value. Lightfastness of the dyes in the polymer matrices has been also investigated. The isomerization and fading kinetics are discussed in terms of polymer structural features as well as of the nature of the dye.