Shape memory and physical properties of poly(ethyl methacrylate)/Na-MMT nanocomposites prepared by macroazoinitiator intercalated in Na-MMT

A macroazoinitiator (MAI) containing a poly(ethylene glycol) (PEG) segment was intercalated in the gallery of sodium montmorillonite (Na-MMT) and this intercalated MAI was used in the preparation of Na-MMT/poly(ethyl methacrylate) (PEMA) nanocomposites via in situ radical polymerization of ethyl methacrylate. The X-ray diffraction pattern and the morphology observed with a transmission electron microscope showed that Na-MMT intercalated with a PEG segment was heterogeneously dispersed in the polymer matrix. Thus Na-MMT intercalated with a PEG segment effectively enhanced the mechanical properties of PEMA. Shape memory behavior and theological properties showed that Na-MMT intercalated with a PEG segment performed its role as a physical crosslinker effectively even with 1.2 wt% of Na-MMT. (c) 2007 Elsevier Ltd. All rights reserved.