Tm. Aminabhavi et Rs. Munnolli, SORPTION, DIFFUSION AND PERMEATION OF ESTERS INTO EPICHLOROHYDRIN ELASTOMER MEMBRANE, Journal of polymer engineering, 14(1), 1995, pp. 53-74
Sorption, diffusion and permeation of five esters into epichlorohydrin
membrane have been studied in the temperature interval of 25 degrees
to 60 degrees C by a sorption gravimetric method. A Fickian diffusion
model was used to estimate the diffusion coefficients. The transport d
ata were found to be dependent on the size of the penetrant molecules,
their interactions with the chain segments of the polymer membrane, t
emperature of the experiment and, to some extent, on the penetrant con
centration within the membrane material. The values of diffusion coeff
icients at 25 degrees C vary from 7.10 x 10(-8) cm(2) s(-1) for methyl
salicylate to 7.12 x 10(-7) cm(2) s(-1) for methyl acetate. The activ
ation energy for the diffusion process falls between 14.78 kJ mole(-1)
to 31.05 kJ mole(-1). Heat of sorption for the aliphatic esters are n
egative while for the aromatic ester, a positive heat of sorption was
observed. The sorption/swelling results have been analyzed by using th
e first order kinetics model. The penetration velocities have also bee
n calculated. The experimental results and the calculated parameters h
ave been used to study the polymer-solvent interactions. None of the s
olvents used in this research has shown any degradative effects on the
membrane used.