| Abstract: | When polymers are used as bearing materials or are processed over tooling under dry sliding conditions, the formation of a transfer layer at the interface controls friction and wear properties. The film formation may be enhanced by the addition of internal lubricants. This article reviews some effects of internal lubricants, such as graphite, polytetrafluoroethylene, and internal silicone oil, on the friction and wear of bulk polymers such as polyimide, polyester, and polyamide. Known lubricating mechanisms are complemented by an interpretation of tribophysical reactions in the sliding interface. Test results are obtained during small and large‐scale laboratory testing under high‐load and high‐temperature conditions and are further related to the effect of contact conditions. The study reveals that some lubricants are not effective under the entire range of sliding temperatures and/or normal loads. For internally lubricated polymers, the efficiency of internal lubricants strongly depends on the contact geometry. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers |
