Study of composite membrane of cellulose acetate or polyvinyl alcohol blended with methylmethacrylate-acrylic acid copolymer for pervaporation separation

In this paper, methylmethacrylate-acrylic acid MMA-AA hydrophilic and hydro phobic copolymers were prepared by copolymerization for preparing membrane materials. The composite membrane of cellulose acetate (CA) blended with MM A-AA hydrophobic copolymer was used for the separation of methanol from pen tane-methanol mixture. When the methanol concentration was only 1 wt%, the permeate flux still maintained at 350 g/m(2)h and separation factor was as big as 800. The composite membrane of PVA (polyvinyl alcohol) blended with MMA-AA hydrophilic copolymer was used for the separation of ethanol-water m ixture. The permeate flux was increased to 975 g/m(2)h at 74 degrees C and the separation factor reached 3000 at 25 degrees C. The PVA/MMA-AA blended membrane surface modified by ammonia plasma was also investigated for separ ating ethanol-water mixture. Both permeate flux and separation factor of th e membrane was improved. However, there was no obvious difference of plasma treatment time in the interval of 20 similar to 40 min.