Synergistic effect of carbon nanotube and clay for improving the flame retardancy of ABSresin

Abstract

Synergistic effect between multi-walled carbon nanotubes (MWNTs) and clay on improvingthe flame retardancy of acrylonitrile–butadiene–styrene (ABS) resin was studied.Flammability properties measured by a cone calorimeter revealed that incorporation ofclay and MWNTs into ABS resin significantly reduced the peak heat releaserate (PHRR) and slowed down the whole combustion process compared to theindividually filled system based on clay or MWNTs. The flame retardancy of theABS/clay/MWNTs nanocomposites was strongly affected by the formation of anetwork structure. Linear viscoelastic properties of the ABS nanocomposites showedthat the coexistence of clay and MWNTs can enhance the network structurewhich can hinder the movement of polymer chains and improve flame retardancy.From transmission electron microscope analysis, MWNTs were shortened aftercombustion and there was no significant change in their diameters. For chars ofABS/clay/MWNTs nanocomposites, some MWNTs ran across between clay layers,indicating a strong interaction existed between clay and MWNTs. The existence of clayenhanced the graphitization degree of MWNTs during combustion. Clay can assistthe elimination of dislocations and defects and the rearrangement of crystallites.Al2O3, one of the components of clay, acts as the catalyst of graphitization.