Lubrication of polyether ether ketone (PEEK) surface by liquid ultrathin films for high wear durability

PEEK, an engineering polymer with many advantages such as lightweight, high thermal stability, high strength coupled with toughness, has often been used as a substitute for metals in applications such as bearings, piston parts, pumps and even biomaterials. However, it shows high coefficient of friction which results in high wear rate when used in tribological applications. This paper seeks to solve tribological problems of high friction and wear for PEEK by applying an ultrathin layer of perfluoropolyether (PFPE) and Multiply-Alkylated Cyclopentane (MAC) lubricants on the surface of PEEK. Results obtained from tribological tests conducted showed that for highly improved tribological performance, there is an optimal initial surface roughness of PEEK surface and lubricant concentration or the thickness of the coatings for both PFPE and MAC lubricant. Also, MAC performs better compared to PFPE for thinner films.