Structural and Tribological Properties of Polytetrafluoroethylene Composites Filled with Glass Fiber and Al₂O₃ in Atomic Oxygen Environment

Abstract

Effects of atomic oxygen (AO) irradiation on the structural and tribological behaviors of polytetrafluoroethylene (PTFE) composites filled with both glass fibers and Al₂O₃ were investigated in a ground-based simulation facility, in which the average energy of AO was about 5 eV and the flux was 5.0 × 10¹⁵/cm² s. It was found that AO irradiation first induced the degradation of PTFE molecular chains on the sample surface, and then resulted in a change of surface morphology. The addition of Al₂O₃ filler significantly increased the AO resistance property of PTFE composites. Friction and wear tests indicated that AO irradiation affected the wear rate and increased the friction coefficient of specimens. The PTFE composite containing 10% Al₂O₃ exhibit the best AO resistance and lower wear rate after long time AO irradiation.

Keywords:

• atomic oxygen
• degradation
• polytetrafluoroethylene
• tribological properties

Acknowledgments

The authors would like to acknowledge the financial support of the National Science Foundation for Distinguished Young Scholars of China (Grant No. 51025517) and the National Natural Science Foundation of China (Grant no. 50805139).