Nanoceramic and polytetrafluoroethylene polymer composites for mechanical seal application at low temperature

Abstract

We investigated the tribochemical and wear properties of Polytetrafluoroethylene (PTFE) based polymer matrix composites with nanoceramic (NC) β-sialon, and Al2O3 particles for the mechanical seal applications at low temperature. SEM showed that NC particles were homogeneously distributed in the polymer matrix and initiated the formation of the supramolecular spherulites around NC. From the temperature stimulated depolarization (TSD) current results, it was analyzed that the surface charge on nanoceramic affected the formation of the spherulites structure. 2 wt% Al 2O3 NC did not degrade the mechanical properties of PTFE so that composites showed the similar values of tensile strength, elongation at the rupture and friction coefficient as those of neat PTFE. However, the composite with 2 wt % Al2O3 NC revealed the improved wear resistance, wear rate of 0.4-1.2 mg/h at room temperature and 0.28 mg/h at -40°C, respectively, while the neat PTFE the 70-75 mg/h at room temperature and 70.3 mg/h at -40°C.