Synthesis and swelling characteristics of poly(N-acryloylglycine) hydrogels

Poly(N-acryloylglycine)(PAcGly) hydrogels were prepared by free-radical polymerization in aqueous solution from N-acryloylglycine(Acgly),N,N-Methylenebis-(acrylamide)(MBA) as crosslinker and(NH4)2S2O8(APS) as initiator,and the PAcGly hydrogel was characterized by infrared spectrometry(FT-IR).Swelling ratio at different pH solutions and the reversible swelling-deswelling properties of hydrogels were measured at the room temperature.Results showed that the appearance of the hydrogels changed from transparent and colorless to opaque and white,and the elasticity changed from elastic to fragile,with the increment of the crosslinker in feed composition.The PAcGly hydrogels swelled drastically with increasing of the pH of solution 2.8～3.8 and swelling reversibility when soaked in pH=1 acid solution and pH=6.8 deionized water alternately.PAcGly hydrogels showed good pH sensitivity and reversible swelling-deswelling property.