Effect of casting solvents and filler quantity on the preparation and physiochemical properties of PVC - Bentonite based composite polymeric membranes

Two series of composite polymeric membranes (cpms) based on poly (vinyl chloride) (pvc) and inorganic filler were prepared by solvent casting method,using tetrahydrofuran (thf) and a mixture of thf and dimethylsulfoxide (dmso). the different percentages (5-35 %) of bentonite clay (79-89 mesh,astm) filler were used. the physicochemical parameters of the cpms i.e. degree of perpendicular swelling,liquid uptake (water,methanol,and ethanol),density,ion adsorption capacity (iac),porosities,electrical resistivity,and conductivities were evaluated. the type-b cpms cast with thf and dmso mixture have greater values of the above parameters except density than the type-a cpms cast with thf only. the cpms having more filler show more liquid uptake. the uptake of water,ethyl alcohol (etoh),5m methanol and methanol (meoh) in type-b cpms was found 8-11,10.12-12.83,3.40-10.88 and 11.37-15.25 times more than type-a cpms. proton ion adsorption capacity of type-b cpms was calculated 2.83 to 8.4 times more than type-a cpms. the porosity range of type-a cpms was observed 0.0377 to 0.093,0.0227 to 0.0909,0.02 to 0.0408 and 0.0476 to 0.1112; whereas porosity range in type-b cpms were noted 0.1955 to 0.4919,0.1477 to 0.4835,0.115 to 0.2554 and 0.1177 to 0.4447 in deionized water,etoh,5m meoh and meoh respectively. the conductivity of type-b cpms was 150-333 times greater than type-a cpms. these all characteristics were compared with pure poly (vinyl chloride) membrane (prepared and studied by same method) cast with dmso and without dmso.