Semi-interpenetrating polymer network (IPN) hydrogels with different compositions of poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA) and poly(acrylamide) (PAAm) were synthesized via free radical polymerization using ethylene glycol dimethacrylate (EGDMA) as crosslinker. The variations of swelling percentages (S%) with time, temperature and pH were determined for all hydrogels. Average S% values at pH=7.4 and 37°C were determined to be 1660% for PAA/PVA, the most swollen hydrogel, and 550% for PAAm/PVA, the least swollen IPN-hydrogel. Swelling behaviors based on ionic and non-ionic components were also explained with detailed SEM micrographs of the hydrogels.
Keywords: Hydrogels; acryl amide; acrylic acid; poly(vinyl alcohol); swelling percentage.