Mechanically strengthened double network composite hydrogels with high water content: a preliminary study

A novel poly(1,2-ethylenediamino) (2-hydroxy-1,3-propanedily) chloride]/ Laponite/polyacrylic acid (PEDAECH/Laponite/PAA) hydrogel was synthesized by two-step solution polymerization combining nanocomposite (NC) strategy with double network (DN). The structural characteristics of resulting hydrogels were investigated by Fourier Transform infrared spectrum (FTIR) and Transmission Electron Microscopy (TEM). A core shell structure was observed in PEDAECH/Laponite composite. The swelling and mechanical strength of the resulting hydrogels were measured when PEDAECH/Laponite composite dose varied. The novel hydrogel achieved a high compressive stress of 148.0 KPa even in higher water content of 98.7% when the PEDAECH/Laponite composite dose is 0.05 ml, the dose of AA was 3.6 ml, N, N??-methylenebisacrylamide (MBAM) dose was 0.04 wt% (based on the weight of AA) and reaction temperature was 0 °C, Based on the cyclic compression studies, there is a small decline in the maximum stress of the hydrogels at the fixed strain of 45% even under three cyclic compressions.