Superabsorbent hydrogels based on an acrylamide/acrylate composite with bentonite or dolomite were synthesized and characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The ideal proportion of acrylamide to acrylate was determined as 1:1. The presence of 10% (m/m) bentonite in the polyacrylamide hydrogel further hydrolyzed with NaOH increased the swelling degree from 1173 to 1270 g water g-1 gel. Being the acrylate obtained by hydrolysis, the hydrogel washing for removal of the alkali excess showed to be a drawback considering the goal of saving water. The initial swelling rate constant and the time required to reach the equilibrium as well as the water absorption capacity (1058 g water g-1 gel) indicate the hydrogel comprised of the poly(acrylamide-co-potassium acrylate) composite containing 10% dolomite as a potential material for use as a soil conditioner. The expected benefit in terms of the efficient use of water should contribute to the water sustainability.
superabsorbent hydrogel; acrylamide; acrylate; bentonite; dolomite; soil conditioner
