Synthesis and mechanical strength of a novel double network nanocomposite hydrogel with core‐shell structure

A novel poly(dimethylimino)(2‐hydroxy‐1,3‐propanedily)chloride]/Laponite/polyacrylic acid (PDMIHPC/Clay/PAA) hydrogel was synthesized by two‐step solution polymerization combining the strategies of both nanocomposite (NC) gels and double network (DN) gels. The chemical composition and core‐shell structure of the hydrogels were confirmed by Fourier transform infrared (FTIR) and transmission electron microscopy (TEM). The mechanical strength was examined by varying the reaction temperature, PDMIHPC/Clay composite dose, N,N′‐methylenebisacrylamide (MBAM) dose and water content. When the reaction temperature was 35°C, PDMIHPC/Clay composite/AA is 1:10 and MBAM dose was 0.050 wt% (based on the weight of AA), the novel hydrogel achieved a best compressive strength of 100.05 KPa with a water content of 98.8%. Copyright © 2011 John Wiley & Sons, Ltd.