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In situ Synthesis of Poly(methyl methacrylate)/Graphene Oxide Nanocomposites Using Thermal-initiated and Graphene Oxide-initiated Polymerization

A facile and cost-effective method to prepare poly(methyl methacrylate) (PMMA)/graphene oxide (GO) nanocomposites was developed by in situ polymerization. By using thermal-initiated and GO-initiated polymerization of methyl methacrylate (MMA), no extra radical initiator was added during the reaction. Without any pre-functionalization of GO, PMMA chains were covalently bonded to its surface, which was confirmed by Fourier-transform infrared, atomic force microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy investigations. TGA analysis showed that the mass ratio of grafted PMMA and GO was as high as 1.7. Transmission electron microscopy and X-ray powder diffraction investigations demonstrated that the grafting of PMMA chains to GO surfaces resulted in homogeneous dispersion of GO sheets in PMMA matrix, which led to a commendable performance on its mechanical and thermal properties. Dynamic mechanical analysis showed that, at a loading level of just 0.5 wt% for the nanocomposites, the storage modulus of the nanocomposites was improved 14%, and the glass transition temperature was increased 12°C in comparison with that of neat PMMA. Thermogravimetric analysis showed that the onset degradation temperature of the nanocomposites was increased 13°C with a GO content of 0.25 wt%.