Some Mechanical Properties of Poly[(acrylic acid)‐co‐(itaconic acid)] Hydrogels

Abstract Two series of hydrogels of poly[(acrylic acid)‐co‐(itaconic acid)] have been prepared by copolymerization in solution using tetrafunctional N,N′‐methylenebisacrylamide (NMBA) as cross‐linker. The resulting polymer was swollen in water at 298 K to yield homogenous transparent hydrogels. These hydrogels were characterized in terms of swelling and compression‐strain measurements. The influence of the comonomer composition and concentration of cross‐linking agent on volumetric swelling and the mechanical properties of these hydrogels were investigated. Inefficient cross‐linking is indicated by the small values of νe relative to the theoretical cross‐linking densities. Dependence of measured affective cross‐linking density (νe) on the theoretical cross‐linking density (νt) for acrylic acid/itaconic acid hydrogels prepared at a fixed composition of AA80/AI20 wt.‐%, but at different concentrations of NMBA. magnified image Dependence of measured affective cross‐linking density (νe) on the theoretical cross‐linking density (νt) for acrylic acid/itaconic acid hydrogels prepared at a fixed composition of AA80/AI20 wt.‐%, but at different concentrations of NMBA.