Study on tribological properties of frictional material based aromatic polyamide

The effect of inorganic fillers on the friction and wear behavior of frictional material bated poly(m-phenylene isophthalamide) (PMIA) is investigated. The polymer composites are prepared by compression molding. The friction and wear of PMIA composites are investigated on a block-on-ring machine by running the PMIA composite block against plain carbon steel. The morphologies of the worn surface of PMIA composite and the ring counterface are examined by using electron probe microanalysis. It is found that copper compounds including CuCl CuCl₂ Cu₂O and CuO filled PMIA exhibit considerably higher friction coefficient than unfilled PMIA while the wear rate of those composites decrease. Especially CuCl is the optimal filler in the copper compounds investigated above. The filled PMIA composite containing CuCl graphite and short carbon fiber shows the best properties for frictional material. The friction coefficient of CuCl-PMIA composite is higher than that of unfilled PMIA because of the abrasive action of CuCl particle. It is probably the smoother surface of counterpart ring and composite block that resulted in the lower wear rate and friction coefficient of PMIA composite.