Swelling studies of copolymeric acrylamide/crotonic acid hydrogels as carriers for agricultural uses

Abstract

In this study, highly swollen acrylamide/crotonic acid hydrogels (in a rod form) containing some inorganic salts such as ammonium nitrate, potassium nitrate and ammonium sulphate used as fertilizer, an agricultural drug such as Dalapon (sodium 2,2-dichloropropionate) and two crosslinkers such as ethylene glycol dimethacrylate and 1,4-butandiol dimethacrylate were prepared by copolymerization of acrylamide and crotonic acid with γ-radiation. As a result of swelling tests, the influence of γ-ray dose and relative content of crotonic acid on the swelling properties, the diffusional behavior of water, diffusion coefficients and network properties of the hydrogel systems were examined. Acrylamide/crotonic acid hydrogels containing these salts and agricultural drug were swollen in the range 2045–400% in water, while polyacrylamide hydrogels swelled in the range 660–700%. Water intake of hydrogels followed a nonFickian-type diffusion. Copyright © 2000 John Wiley & Sons, Ltd.