Synthesis and properties of poly(methyl methacrylate)/clay nanocomposites using natural montmorillonite and synthetic Fe-montmorillonite by emulsion polymerization

In this article, Fe-montmorillonite (Fe-MMT) was synthesized by hydrothermal method. For the first time, Fe-MMT was modified by cetyltrimethyl ammonium bromide (CTAB), and poly(methyl methacrylate)(PMMA)Fe-MMT nanocomposites were synthesized by emulsion polymerization. Then poly(methyl methacrylate)(PMMA)/ natural montmorillonite (Na-MMT) and PMMA/Fe-MMT nanocomposites were compared by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) patterns, transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). By XRD and TEM, it was found out that the morphology of PMMA/Fe-MMT nanocomposites was different from that of the PMMA/Fe-MMT nanocomposites when the content of two types of clay was same in the PMMA matrix. It was possible that the presence of iron may lead to some radical trapping, which enhances intragallery polymerization to be developed to improve layer dispersion in PMMA/Fe-MMT systems. In TGA curves, the thermal stability and residue at 600 degrees C of PMMA/Fe-MMT nanocomposites were higher than those of PMMA/Na-MMT nanocomposites. Those dissimilarities were probably caused by structural Fe ion in the lattice of Fe-MMT.