INTERACTIONS OF CHLOROSULFONATED POLYETHYLENE GEOMEMBRANES WITH ALIPHATIC ESTERS - SORPTION AND DIFFUSION PHENOMENA

The resistance of chlorosulfonated polyethylene geomembranes to nine aliphatic esters viz., methyl acetate, ethyl acetate, methyl acetoacetate, ethyl acetoacetate, n-butyl acetate, diethyl oxalate, iso-amyl acetate, diethyl malonate, and diethyl succinate was investigated in the temperature interval 25-60 degrees C by measuring the liquid sorption using a gravimetric method. A Fickian diffusion equation was used to calculate the diffusion coefficients, and these data were dependent on the type of ester molecules and their interactions with the geomembrane, in addition to temperature and solvent concentration. The activation energy values for the diffusion process were in the range 18-41 kJ/mole and the heat of sorption varied from 0.61 to 18.50 kJ/mole. The sorption/swelling results were found to follow the first order kinetics. Solvent front velocities were calculated from the sorption data. The statistical error analysis has been presented in order to judge the reliability of the technique used. The experimental data and calculated parameters were used to discuss transport results in terms of membrane-solvent interactions. None of the esters showed any degradative effects on the geomembrane used.