Effect of matrix morphology on the wear and friction behavior of alumina nanoparticle/poly(ethylene) terephthalate composites

The friction and wear properties of poly(ethylene) terephthalate (PET) filled with alumina nanoparticles were studied. The nanoparticle loading was varied from 1 to 10 wt.%. The nanocomposite samples were tested in dry sliding against a steel counterface. The results show that the addition of nanoparticles can increase the wear resistance by nearly 2× over the unfilled polymer. The average coefficient of friction also decreased in many cases. The nanocomposites form a more adherent transfer film that protects the sample from the steel counterface, although the presence of an optimum filler content may be due to the development of abrasive agglomerates within the transfer films in the higher wt.% samples. This study varied both crystallinity and weight percent of filler in a PET matrix in an attempt to separate the effects of nanofillers and crystallinity on the tribology.