Chemical modification of multiwalled carbon nanotubes by polyethylene-grafted maleic anhydride

Multiwalled carbon nanotubes(MWCNTs) were oxidized by an acid mixture(concentrated H2SO4∶HNO3 =3∶1v/v) to form carboxyl groups,which were then reacted with anhydride ethylene diamine by an amidation reaction to introduce amine end groups that were subsequently grafted to polyethylene/maleic anhydride copolymer(PE-g-MA) to increase the dispersion of the modified MWCNTs in a polyethylene(PE) matrix.The chemical modification of the MWCNTs was verified by FTIR,XPS and Raman spectroscopy.The modified MWCNT/PE composites exhibited an electrical percolation threshold at 0.67 vol% MWCNTs.The volume resistivities of the modified MWCNT/PE composites decreased from 1016 to 105 Ω · m with increasing MWCNT content from 0.1 to 1.2 vol%.