The effects of the variations of carbon nanotubes on the micro-tribological behavior of carbon nanotubes/bismaleimide nanocomposite

Two kinds of original multiwalled carbon nanotubes (MWCNTs) with different diameters, and one carboxyliated MWCNTs were used to prepare three kinds of MWCNTs/bismaleimide (BMI) nanocomposites. The effects of the diameter, concentration and functional group of MWCNTs used in the composites on the micro-tribological behavior of the MWCNTs/BMI nanocomposites were investigated in this paper. The microhardness, the morphology of the worn surface, the glass transition temperature and dynamic mechanical properties of the MWCNTs/BMI nanocomposites were also measured to figure out the possible main wear mechanism of the composites. Results show that the addition of MWCNTs in BMI resin decreases the friction coefficient of the resin no matter what kind of MWCNTs is added. Moreover, the wear loss rate of all nanocomposites considerably decreases with the increasing of nanotube content until the content reaches 2.5 wt%. Functionalization of MWCNTs changes the main wear mechanism of the MWCNTs/BMI composite from adhesive wear (for pure BMI resin) to abrasive attrition by changing the self-lubricating property of the wore surface, the dispersion of MWCNTs in the BMI matrix, the interfacial strength between MWCNTs and the matrix as well as the internal strength of the materials. (c) 2007 Elsevier Ltd. All rights reserved.