PDMAA/Clay nanocomposite hydrogels based on two different initiations

The poly(N,N'-dimethylacrylamide)/clay (PDMMA/Clay) nanocomposite hydrogels cross-linked by inorganic clay Laponite XLG were prepared via free radical polymerization by using potassium peroxodisulfate (KPS) and azobisisobutryonitrile (AIBN) as initiators separately. The structure, morphology, swelling degree and mechanical properties of the hydrogels based on different initiation were investigated. The results indicated that the clay were exfoliated and dispersed randomly in the hydrogels, which acted as a multifunctional cross-linker. The swelling ratios of the nanocomposite hydrogels decreased with increasing the clay content. The hydrogel initiated by AIBN had better mechanical properties and swelling ratio than that initiated by KPS. (C) 2011 Elsevier B.V. All rights reserved.