Evolution of Microstructure and Physical Properties of PMMA/ MWCNTs Nanocomposites upon the Addition of Organoclay

The present investigation was carried out to evaluate the application of Cloisite 30B organoclay (C30B) on the rheological, structural, electrical, and thermal characteristics of poly (methyl methacrylate)/multiwalled carbon nanotubes nanocomposites (PMMA/MWCNTs) fabricated by the simultaneous melt mixing. The microstructure and the state of nanofillers dispersion were assessed by melt linear viscoelastic experiments, X-ray diffraction (XRD), and electron microscopy. The obtained results illustrated that the applied C30B nanofiller considerably altered the pattern of MWCNTs dispersion and reaggregation. The study of electrical properties of single filler and hybrid nanocomposites also showed that the percolation threshold almost remained intact with the addition of C30B ( c φ ~0.18%), but an effective decrease in volume resistivity was observed at high MWCNTs loading levels. Finally, thermal analyses, employed as complementary experiments, confirmed that the MWCNTs dispersion was improved by the incorporation of C30B nanofillers. Upon the incorporation of nanofillers, a decrease in tanδ peak height and a small increase in Tg were observed. The Td,5%, Td,70%, and Tmax of the neat PMMA were 308, 342.9 and 335.2 °C, respectively while for the PMMA- 0.5%MWCNTs-3%C30B, they stood at 314.7, 380.3 and 369.2 °C, respectively.