Swelling kinetics of poly(acrylamide)/poly(mono-n-alkyl itaconates) hydrogels

Hydrogels of mono-n-alkyl itaconate/N-acrylamide have been synthesised. The swelling process at three different pH values (acid, neutral and basic) has been studied. The experimental data indicate that our hydrogels follow second-order swelling kinetics. According to this, the kinetic constant, K_∞, and the swelling capacity at equilibrium, W_∞, have been calculated. The influence of the solvent pH and the molar mass of the mono-n-alkyl itaconate monomeric unit has been analysed. It seems that the general balance between the hydrogen bonding and the hydrophobic interactions regulates the swelling process of these hydrogels.