Tribological behaviour of carbon nanotubes/polyurethane nanocomposite coatings

The organosilane-modified carbon nanotubes (CNTs-Si)/polyurethane (PU) nanocomposite coatings were fabricated by a spraying technique. Tribological behaviours of these nanocomposite coatings were investigated using a ring on block wear tests under dry friction conditions, and worn surfaces and transfer films formed on the surface of counterpart ring were studied by scanning electron microscope and optical microscope, respectively. The results indicated that the addition of the low inclusion of CNTs and CNTs-Si can improve the reducing-friction and anti-wear abilities of the PU coating, and CNTs-Si as the filler was superior to CNTs in terms of the ability of decreasing the friction coefficient and the wear rate of the PU coating. In both cases, appropriate treatments could effectively improve the tribological properties in the PU composite coatings owing to the enhanced CNT/matrix interfacial bonding.