AN ASSESSMENT OF CHEMICAL COMPATIBILITY OF BROMOBUTYL RUBBER, CHLOROSULFONATED POLYETHYLENE AND EPICHLOROHYDRIN MEMBRANES IN THE PRESENCE OF SOME HAZARDOUS ORGANIC LIQUIDS

The present study addresses the currently available polymeric materials which are possibly used as liner materials in waste chemical ponds against hazardous organic liquids. To assess the chemical compatibility, bromobutyl rubber (BIIR), chlorosulfonated polyethylene and epichlorohydrin (ECO) are selected for exposure to chloroalkanes and non-chlorinated liquids. These solvents come under the category of hazardous liquids and protection from their contamination to ground water and other aquatics is an important hygienic requirement. One of the possible means of studying the chemical compatibility of the liner membranes against such liquids is to investigate their transport characteristics into the membrane matrices. Thus, results of sorption and diffusion of the above-mentioned systems in the temperature interval 25-60-degrees-C are presented using the sorption gravimetric technique. These results are analyzed by using the Fickian equation. The dependence of transport coefficients on the size and shape of the liquid molecules is discussed. Transport results are greatly influenced by the type of the polymer-solvent interactions in addition to the size of the liquid molecules. The Arrhenius activation parameters are estimated from a temperature dependence of sorption, diffusion and permeation coefficients. Enthalpy and entropy of sorption for the polymer-solvent systems have also been studied. Computed parameters and experimental results are used to discuss the transport mechanism in terms of the type and nature of the polymer membranes and the solvent molecules. Volume dilation of the polymers in the presence of the chosen liquid media has been measured. BIIR and ECO membranes appeared to be reactive toward tetrahydrofuran at 60-degrees-C.