Enhanced thermo-mechanical, thermal and EMI shielding properties of MWNT/MAgPP/PP nanocomposites prepared by extrusion

Abstract

In this work, multiwalled nanotube/maleic anhydride–grafted polypropylene/polypropylene (MWNT/MAgPP/PP) nanocomposites are produced using an industrially relevant twin-screw extrusion process. The composites with varying nanotube content in the range of 0.5 wt% to 2 wt% were synthesized and evaluated for their thermo-mechanical (i.e., Vicat softening temperature (VST), heat deflection temperature (HDT)), thermal (i.e., Melting (Tm) temperature, crystallization (Tc) temperature and thermal decomposition (Td) temperature), and electromagnetic interference (EMI) shielding properties. The scanning electron microscopy (SEM) of composite cross-sections reveal uniform dispersion of MWNTs in the polymer matrix. Overall, the MWNT content in the composites was found to influence the composite properties with higher nanotube loadings resulting in a higher increase in the measured properties over the MAgPP/PP sample. The composite containing 2wt% MWNTs exhibited the highest increase of 33.42%, 15.52%, 15.42%, 10.23%, over the pure MAgPP/PP sample in its Tdi, Tdf, VST and HDT values, respectively. The electromagnetic interference (EMI) shielding effectiveness of 2 mm thick sample containing 2wt% MWNTs content was measured to be 5.9 dB in the X-Band frequency range of 8–12.4 GHz, which corresponds to 74.29% attenuation of incident wave power. The results obtained suggest the viability of the masterbatch based extrusion method as a potential strategy for the large-scale production of nanocomposites.