In situ Preparation of Aramid-MWCNT Nano-composites: Morphology, Thermal Mechanical and Dielectric Properties

In situ polymerization technique was used to link chemically the amine-terminated high molecular weight aramid chains with acid-functionalized MWCNTs. The The X-ray photoelectron spectroscopy (XPS) was used to study the chemical linkage between aramid chains and MWCNTs and the composite morphology was investigated by scanning electron microscopy. Dynamic mechanical analysis (DMA) showed a higher increase in the storage modulus. The temperature involving α-relaxations on MWCNTs loading was found higher in comparison to the system where pristine MWCNTs were used. Iinterfacial interactions between the matrix and MWCNTs including hydrogen bonding, π–π stacking and chemical bonding are considered the key parameters responsible and the chemical bonding of the MWCNTs with the matrix resulted in better dispersion of CNTs and the higher visco-elastic properties. The maximum glass transition and the thermal decomposition temperature of these composites respectively were observed around 346°C and 533°C. The inclusion of pristine CNTs increased the electric conductivity of the aramid films with a minimum threshold value at the loading of 1.67 vol.%. Such mechanically strong and thermally stable aramid composites are suitable for many applications including high performance materials for electromagnetic shielding and radar absorption.