The multiply walled carbon nanotubes (MWCNTs) were methylolated using eletrophilicity of formaldehyde and then grafted by maleic anhydride. The MWCNTs could be characterized by transmission electron microscope (TEM), IR and Zeta potentiometer. The TEM examination showed that the MWCNTs grafted by maleic anhydride were coated. The IR spectra showed that there were many hydroxyl and methylene groups on the surface of the methylolated MWCNTs, ester and methylene ones on the MWCNTs grafted by maleic anhydride. In addition, the optical microphotography showed that the dispersion of methylolated MWCNTs in water was improved significantly. And then, the dispersion of the grafted MWCNTs in xylene was enhanced remarkably. Zeta potential measurements showed that methylolated MWCNTs in water obtained more negative electricity, the MWCNTs suspension obtained higher dispersibility and stability.

Key words: multi-walled carbon nanotube, methylolated, maleic anhydride, graft esterification