Polyvinyl alcohol-polyacrylamide interpenetrating polymer network membranes and their pervaporation characteristics for ethanol-water mixtures

Abstract

Crosslinked polyvinyl alcohol-polyacrylamide interpenetrating polymer networks (PVA-PAAM IPN) were synthesized by the sequential IPN technique. Glutaraldehyde (GAL) and N, N′-methylenebisacrylamide (BisAAM) were used as crosslinking agents for the PVA and PAAM networks, respectively. The PVA_PAAM IPN membranes have been prepared starting from an aqueous solution of PVA to which AAM, BisAAM and potassium persulfate were added. After polymerization, GAL was introduced in the solution and the latter was cast on a glass plate. The effect of the content of each of the crosslinking agents on the uncrosslinked fraction dissolved in water was determined. The swelling of the membranes in water and in the mixtures: water-ethanol and water-acetic acid was also investigated. The mechanical properties of the membranes were studied via tensile testing. The compositions of water-ethanol and water-acetic acid mixtures sorbed in the membranes were determined. The pervaporation of water-ethanol mixtures through the PVA-PAAM IPN membranes was investigated.