A performance study of polyvinyl butyral blended cellulose acetate based semipermeable membranes

The possibility of blending polyvinyl butyral (PVB) with cellulose acetate (CA) for synthesizing functionally useful semipermeable membranes was looked into and ascertained. The performance of PVB-CA blend membranes was studied under different membrane preparation conditions, namely, nature of solvent, solvent ratio, presence of additive, polymer blending ratio, solvent evaporation period and thermal annealing. The membrane performance was reported for aqueous sodium chloride solutions at transmembrane pressures not exceeding 20Kg/cm(2). The mechanical strength data of PVB-CA blend membrane are compared with that of CA membrane. The studies on the chemical stability of PVB-CA membranes indicate the relative superior alkaline stability.