A Conductive Carbon Nanotube-Polymer Composite Based on a Co-continuous Blend

Abstract

A conductive carbon nanotube (CNT) based polymer composite was constructed in which the conductive network utilized the selective distribution of CNTs in a co-continuous phase polymer blend. CNTs were first uniformly coated on the surface of polyethylene (PE) fine particles through alcohol assisted dispersion under ultrasonication, and then the CNTs coated PE particles were melt compounded with polycarbonate (PC). The theoretical prediction from both thermodynamics and kinetics indicated the CNTs mainly stayed at the interface between PC and PE. Rheological measurements and scanning electron microscopy (SEM) and optical microscopy (OM) observations provided the evidences for the selective distribution of CNTs and revealed the transition from the dispersed/matrix phase structure to the co-continuous phase structure at 50 wt% of PC. As PE and PC formed co-continuous phases, the CNTs formed a perfect conductive network on the phase interfaces, which resulted in a percolation threshold between 0.3 and 0.5 vol%, a relatively low value for CNTs filled thermoplastic composites reported in the literature.

Keywords:

• carbon nanotubes
• co-continuous blend
• conductive polymer composite
• percolation threshold
• preferable distribution

Acknowledgments

This work was financially supported by the National Outstanding Youth Foundation of China (Grant No. 50925311) and National Program for High Technology Research and Development of China (Grant No. 2008AA03Z510).