Fabrication of fullerene-decorated graphene oxide and its influence on flame retardancy of high density polyethylene

Fullerene (C-60) decorated graphene oxide (GO), denoted as GO-d-C-60, was synthesized through a three step chemical process, including acylating chlorination of GO, amino-functionalization of GO and addition reaction of C-60 molecules with amino groups, with the purpose of promoting the dispersion of GO in high density polyethylene (HDPE) and further improving thermal stability and flame retardancy of HDPE/ GO composite. Infrared spectroscopy (IR), transmission electron micrographs (TEM) and X-ray photoelectron spectroscopy (XPS) proved that about 2.3 wt.% of C-60 molecules, with the size of about 40-70 nm, were bonded onto the surface of GO and mainly located on the edge of GO sheets. The chemical decoration made GO-d-C-60 to have better dispersion in HDPE than GO, favoring the formation of compact and integrated char barriers when heated or ignited. Consequently, GO-d-C-60 improved the thermal stability and flame retardancy of HDPE more effectively than pristine GO, due to the assembly of the barrier effect of GO and the radical-trapping effect of C-60. (C) 2016 Elsevier Ltd. All rights reserved.