Graphene nanoplate and multiwall carbon nanotube-embedded polycarbonate hybrid composites: High electromagnetic interference shielding with low percolation threshold

This study has reported the preparation of polycarbonate (PC)/graphene nanoplate (GNP)/multiwall carbon nanotube (MWCNT) hybrid composite by simple melt mixing method of PC with GNP and MWCNT at 330 degrees C above the processing temperature of the PC (processing temperature is 280 degrees C) followed by compression molding. Through optimizing the ratio of (GNP/MWCNT) in the composites, high electromagnetic interference shielding effectiveness (EMI SE) value (approximate to 21.6 dB) was achieved at low (4 wt%) loading of (GNP/MWCNT) and electrical conductivity of approximate to 6.84 x 10(-5) S.cm(-1) was achieved at 0.3 wt% (GNP/MWCNT) loading with low percolation threshold (approximate to 0.072 wt%). The high temperature melt mixing of PC with nanofillers lowers the melt viscosity of the PC that has helped for better dispersion of the GNPs and MWCNTs in the PC matrix and plays a key factor for achieving high EMI shielding value and high electrical conductivity with low percolation threshold than ever reported in PC/MWCNT or PC/graphene composites. With this method, the formation of continuous conducting interconnected GNP-CNT-GNP or CNT-GNP-CNT network structure in the matrix polymer and strong - interaction between the electron rich phenyl rings and oxygen atom of PC chain, GNP, and MWCNT could be possible throughout the composites. POLYM. COMPOS., 37:2058-2069, 2016. (c) 2015 Society of Plastics Engineers