Combining Atom Transfer Radical Polymerization and Melt Compounding for Producing PMMA/Clay Nanocomposites

Nanocomposites based on poly (methyl methacrylate) (PMMA) and 3 wt % of clay (montomorillonite) organomodified with alkylammonium cations bearing alkyl halide function (OCTANBr(i)BBr-CL) have been obtained by melt blending. The nanohybrid masterbatch approach, already used within other matrices, has also been tested to produce this type of material. Accordingly, highly filled (similar to 30 wt %) PMMA-OCTANBr(i)BBr-CL nanohybrid has been synthesized by atom transfer radical polymerization (ATRP) of MMA as in situ initiated from the alkyl halide functions decorating the nanoclay surface. This nanohybrid, i.e., PMMA-grafted organomodified clay, has been added as masterbatch and melt-blended within commercial PMMA. A significantly better clay nanoplatelet dispersion of the samples prepared via the masterbatch process was evidenced by wide-angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). As a result, these exfoliated nanocomposites proved to be characterized by better thermal and mechanical properties than the more conventional physical blends, as evidenced by thermogravimetrical analysis (TGA) and dynamical mechanical analysis (DMTA), respectively. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 1355-1364, 2011