Thermal stability of Multi walled Carbon nanotubes (MWCNTs) /Polymer mixture Nanocomposites

Abstract

Carbon nanotubes (CNTs) were synthesized, purified and then functionalized with different concentrations of HNO3/H2SO4 and HNO3/H2O2 mixture for different time. Polyaniline, Polypyrrole, Epoxy, Polystyrene nanocomposites with CNTs and their novel mixtures were synthesized via in-situ polymerization technique successfully. Their composition, morphology, degree of dispersion, particle size was determined by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) & X-ray powder diffraction (XRD). Thermal stability of novel nanocomposites was determined by Thermal gravimetric analysis (TGA) and Differential scanning calorimetry (DSC). XRD results showed the presence of both CNTs crystalline phase as well as that of amorphous phase of polymer/polymers having crystallite size in nano-domain (20.3- 53.3 nm). FT-IR spectra showed the carboxylic group functionalization of synthesized CNTs, while in composites there is clear appearance of polymer matrix functional groups as well as that of CNTs IR active identities. SEM & TEM results showed the formation of composites having nano-domain morphology and proper dispersion of CNTs in polymer matrix. TGA and DSC results showed the thermal stability of nanocomposites is increased as compared to pure polymers reported values. TGA curves showed the enhanced thermal stability of end mixture with 31% char yield at 1000C. Enhancement in Glass transition temperature was clear from DSC results as Tg values of mixtures attained in our research work was APE ~268 C, APES~ 339 C. Novel nanocomposites showed improved thermal stability so they proved their potential use in aerospace application