Tribological investigation of the effects of particle size, loading and crystallinity on poly(ethylene) terephthalate nanocomposites

The friction and wear properties of poly(ethylene) terephthalate (PET) filled with alumina nanoparticles were studied. The test matrix varied particle size, loading and crystallinity to study the coupled effects on the tribological properties of PET-based nanocomposites. The nanocomposite samples were tested in dry sliding against a steel counterface. The wear rate ranged from 2 × 10−6 to 53 × 10−6 mm3/Nm and the friction coefficient ranged from 0.21 to 0.41. Crystallinity was found to be a function of the processing conditions as well as the particle size and loading, while tribological properties were affected by crystallinity, filler size and loading. Wear rate and friction coefficient were lowest at optimal loadings that ranged from 0.1 to 10 depending on the crystallinity and particle size. Wear rate decreased monotonically with decreasing particle size and decreasing crystallinity at any loading in the range tested.