Synthesis and characterization of poly(AAm-co-BMA-co-AAc) hydrogels: effect of acrylamide content on swelling behaviour

Abstract

Abstract Poly(acrylamide-co-butyl methacrylate-co-acrylic acid) hydrogels were prepared in various concentrations of a dioxane/water mixture as polymerization media using different percentages of cross-linker and by varying the amount of acrylamide over 4-fold in order to study the effect of acrylamide content on swelling behaviour of hydrogels. It was found that hydrogels prepared in 50% aqueous dioxane solution exhibited the highest swelling. The results also indicated that with increasing acrylamide content, swelling increased initially. And when acrylamide content further increased to 66% (based on total monomer), the swelling decreased gradually. Detailed swelling kinetics, such as swelling ratio, transport exponent n and diffusion coefficient D, were studied and the effect of pH on equilibrium swelling was also studied. The hydrogels were also characterized by network parameters, such as molecular weight between cross-links (M c) and cross-link density (q), that were determined to explain the swelling behaviour. The hydrogels were also characterized by Fourier transform infrared spectroscopy, elemental analysis, differential scanning calorimetry and scanning electron microscopy. Keywords: HYDROGELSPOLY(AAM-CO-BMA-CO-AAC)SWELLING BEHAVIOURNETWORK PARAMETERSSWELLING KINETICS