Self-curing membranes of chitosan/PAA IPNs obtained by radical polymerization: preparation, characterization and interpolymer complexation

Chitosan/polyacrylic acid IPN's were prepared by radical polymerization of acrylic acid, AA, activated at low temperature, in an aqueous/alcoholic chi tosan dispersion. AA monomer to polymer conversion and membrane composition s were determined by elemental analysis and FTIR. Evidences of interpolyele ctrolite complex formation were found from the FTIR spectra as well. The gr avimetric measurements and the elemental analysis after some exhaustive PAA extraction support the existence of some PAA grafting on the reactive amin e group of the chitosan. Swelling degree of the membranes is highly depende nt on pH and composition, showing a higher swelling in membranes richer in AA and increased pH due to the breaking of interpolyelectrolite salt bonds. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.