Segregated network formation of multiwalled carbon nanotubes in natural rubber through surfactant assisted latex compounding: A novel technique for multifunctional properties

In the present study Vulcastab VL (polyethylene oxide condensate) has been used as a non-ionic surfactant to get stable aqueous dispersions of multiwalled carbon nanotubes (MWCNTs). Sonication time and surfactant concentration were optimised by UV-vis spectroscopy and dynamic light scattering technique. Homogeneously dispersed surfactant coated individual MWCNTs in water were clearly evident from Transmission electron microscopy (TEM). Natural rubber-Multiwalled carbon nanotube (NR-MWCNT) nanocomposites were prepared by latex stage mixing. Instead of being randomly dispersed, MWCNTs were found to retain at the boundary of rubber particles resulting in a segregated network as evidenced from TEM. Addition of very small amount of MWCNT showed remarkable improvement in mechanical, thermal, electrical and barrier properties of NR. Segregated network of CNTs resulted in very low electrical percolation threshold (0.043 vol%) for the composite with enhanced dielectric properties. (C) 2017 Published by Elsevier Ltd.