Effect of transfer film on tribological behavior of polyamide 66-based binary and ternary nanocomposites

BACKGROUND: In a polymer-metal sliding system, the formation and performance of the transfer film have important effects on the tribological behavior of the polymer. In order to reveal the wear mechanism of polyamide 66 (PA 66) and its composites consisting of styrene-(ethylene/butylene)-styrene triblock rubber grafted with maleic anhydride (SEBS-g-MA) particles and organoclay nano-layers, the tribological behavior and transfer films of polyamide 66 and its composites were investigated under dry sliding. RESULTS: The incorporation of SEBS-g-MA rubber particles reduces the wear mass loss of PA 66, while the addition of organoclay nano-layers increases the wear mass loss. The transfer films formed by neat PA 66 and PA 66/organoclay binary nanocomposite include a dark portion and bright portion. In the dark portion, the transfer film is thicker; in the bright portion, the steel ring surface is exposed. The transfer film formed by PA 66/SEBS-g-MA/organoclay ternary nanocomposite is thinner and more uniform than the transfer films formed by the other materials. CONCLUSION: When SEBS-g-MA rubber particles and organoclay nano-layers are added simultaneously to PA 66, the wear resistance of PA 66 can be improved markedly. The main reason is that PA 66/SEBS-g-MA/organoclay ternary nanocomposite can form a thin and uniform transfer film on the steel ring surface. (c) 2008 Society of Chemical Industry.