Poly(2-hydroxyethyl methacrylate) Nanocomposites: From a Nonionic Gel to pH Sensitivity

Abstract

2-Hydroxyethyl methacrylate (HEMA)-clay nanocomposites were prepared via in situ free radical polymerization using montmorillonite (MMT) as a crosslinker. The structure and surface morphology of the nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, and scanning electron microscopy. It was found that exfoliated or highly expanded intercalated nanocomposite structure was obtained. The swelling degree was determined in distilled water and various pH buffered solutions. The highest swelling capacity in distilled water was observed for the nanocomposite sample prepared with the MMT amount of 10 % (w). It was seen that the diffusion mechanism was Fickian type in distilled water and also in various pH-buffered solutions. It is interesting that the swelling degree of nanocomposites in alkaline pH values increased by the increasing of MMT in the polymer structure. This result supports the possibility of future applications of the novel nanocomposite in systems for the controlled released of drugs. POLYM. COMPOS., 32:2062-2069, 2011. (C) 2011 Society of Plastics Engineers