Swelling studies of super water retainer acrylamide/crotonic acid hydrogels crosslinked by trimethylolpropane triacrylate and 1,4-butanediol dimethacrylate
Superswelling acrylamide/crotonic acid (AAm/CA) hydrogels were prepared by free radical polymerization in aqueous solution of acrylamide (AAm) with crotonic acid (CA) as comonomer. For each copolymerization, four different composition of CA and a concentration of multifunctional crosslinkers such as trimethylolpropane triacrylate (TMPTA) and 1,4-butanediol dimethacrylate (BDMA) were used. As a result of dynamic swelling tests, the influence of the crosslinkers and the relative content of CA on the swelling properties were examined. AAm/CA hydrogels were swelled in the range of 1520-2980% in water, while AAm hydrogels swelled as 780 and 1360%. Equilibrium water content of AAm/CA hydrogels was calculated in the range of 88.73 and 96.75%. Water uptake of hydrogels was followed non-Fickian type diffusion.