Study on Pervaporation Performance of PVA/P(AA-Co-AN)/PVA Membrane

The PVA/P(AA-Co-AN)/PVA composite membrane was prepared to separate methanol from aqueous solution.Acrylic acid(AA) and acrylonitrile(AN) were synthesized by the solution polymerization with nanometer SiO2.The copolymer solution P(AA-Co-AN) was made into the main body of the membrane,with the polyvinyl alcohol(PVA) acetal membrane on both sides,to make the composite pervaporation membrane.The swelling behavior of membrane in the methanol dense aqueous solution was explored.The effect of the dipping temperature and concentration on the swelling degrees was also measured.The mechanical property of the membrane was investigated by the stretching test.The performances of the membranes prepared with different n(AA)∶n(AN) ratios were investigated through pervaporation experiments at different temperatures and different feed compositions.The results of swelling and pervaporation experiments show that the membrane has an encouraging swelling and pervaporation behavior in the methanol dense aqueous solution.The membrane prepared with n(AA)∶n(AN)=1∶1 gave the highest separation factor of 1 534 and a permeation flux of 583 g/(m2·h) at 60 ℃ in the pervaporation of the w(methanol)=98% aqueous solution.