Reducing resistivity of polyamide-6/multi-walled carbon nanotube composites by adding ultra-fine rubber particles on account of non-volume exclusion effect

The volume resistivity of polyamide-6(PA6)/multi-walled carbon nanotube (MWCNT) composites was found to be further reduced by adding a kind of ultra-fine rubber particle (URP) with average diameter of 150 nm due to non-volume exclusion effect. With the addition of 16 phr URP, the percolation threshold of PA6/MWCNT composites was reduced from 6 phr MWCNTs to 3 phr. Besides, at a constant loading of 4 phr MWCNTs, increase of URP loading led to two changes and a plateau for the volume resistivity of composites. The morphological observations of composites revealed that the decrease of volume resistivity was attributed to both homogenous dispersion and stretching of MWCNTs in PA6. The mechanism on better dispersion and stretching of MWCNTs with the help of URP was also given.