Temperature effects during the sorption and desorption of water vapor in high polymers. Part II. Films with special reference to ethyl cellulose

The effect of the heat of sorption on the rate of sorption of water vapor in polymer films has been investigated. A mathematical analysis has been made and equations developed for correcting the rates of sorption and desorption for the accompanying heat effects. An experimental study has been carried out for the case of ethyl cellulose film and the heat transfer and other coefficients determined to enable the diffusion constants to be correctly estimated. Good agreement was obtained with the corrected values at different sorption intervals.