Modification of CNT and its effect on thermo mechanical, morphological as well as rheological properties of Polyether Imide (PEI)/Liquid Crystalline Polymer (LCP) blend system

Abstract

This work analysed the effect of physical and chemical interactions between the modified mutiwalled carbon nanotubes (MWCNTs) and the Polyetherimide/Liquid crystalline polymer (PEI/LCP) blend matrix, on the dispersion of MWCNTs and deformation of LCP particles. Silicon Carbide (SiC) and TiO2 coated MWCNTs were prepared from polycarbosilane and titanium (IV) n- butoxide precursors, respectively, by sol–gel process to improve their dispersion in the polymer matrix. Formation of both was confirmed by X-Ray diffraction (XRD), Transmission Electron Microscope (TEM) and X-Ray photoelectron Spectroscopy (XPS) studies. Polyetherimide (PEI)/liquid crystalline polymer (LCP) blends with unmodified and modified MWCNTs were prepared by melt blending. TEM and Field Electron Scanning Electron microscope (FESEM) studies revealed better dispersion of modified MWCNT in the polymer matrix than the unmodified one. Rheological analysis of hybrid composite systems containing modified and unmodified MWCNT revealed that nano composite containing TiO2 coated MWCNT has the lowest viscosity and this is due to fibrillation of LCP. Superior thermal stability of modified MWCNT added composites was confirmed from thermo-gravimetric analysis (TGA). Dynamic mechanical thermal analysis (DMTA) and Differential Scanning Calorimetry (DSC) studies showed the variation in glass transition temperature (Tg) of the composites in presence of pure and modified MWCNT. Mechanical properties of nanocomposites with TiO2 coated MWCNTs were found to be higher than that of pure MWCNTs added nanocomposite.