Enhancing electrical and tribological properties of poly(methyl methacrylate) matrix nanocomposite films by co-incorporation of multiwalled carbon nanotubes and silicon dioxide microparticles

Abstract

Multiwalled carbon nanotubes (MWCNTs) and silicon dioxide microparticles (SiO2-MPs) were co-incorporated in poly(methyl methacrylate) (PMMA) matrices to form PMMA/MWCNT-SiO2-MP nanocomposite films. The SiO2-MP content in the nanocomposite films was varied at a fixed MWCNT content of 4 wt% to investigate the effect of SiO2-MP content on the electrical and tribological properties of the PMMA/MWCNT-SiO2-MP nanocomposite films. The co-incorporation of MWCNTs and SiO2-MPs dramatically lowered the electrical resistance of the nanocomposite films compared to that of the PMMA film, while higher fractions of SiO2-MPs more effectively promoted the decrease in the electrical resistance of the nanocomposite films by improving the conductive networks formed by the MWCNTs in the PMMA matrices. Although the friction of the nanocomposite films significantly increased with increased SiO2-MP content due to the promoted mechanical interlocking between the surface asperities of two mating surfaces, the wear of the nanocomposite films was much less severe than that of the PMMA film during ball-on-disc tribological tests.