Preparation and characterization of hydrophobically modified polyacrylamide hydrogels by grafting glycidyl methacrylate

A modified polyacrylamide (PAM-g-GMA) has been prepared by ring-opening reaction of glycidyl methacrylate (GMA) monomer grafted onto the –COO⁻ groups of partially hydrolytic polyacrylamide (PAM) chain. The modified polyacrylamide hydrogels were obtained via a free radical polymerization of PAM-g-GMA without adding any a crosslinker using potassium persulfate (KPS), as initiator, and triethanolamine (TEA), as a coupling agent in aqueous solution. The molecular structure of PAM-g-GMA was characterized by FT-IR, ¹H-NMR, and the thermal behaviors of hydrogels were studied by DSC. Furthermore, the swelling property and compressive properties of PAM-g-GMA hydrogels were investigated. The results show that the modified polyacrylamide hydrogels exhibit a remarkable hydration-dehydration change in response to pH in aqueous media and also undergo dramatic increase in volume with increasing temperature. So the modified polyacrylamide hydrogels will have promising and wide applications such as pharmaceutical use, water retention, electrophoretic media and so on.