Abstract: In this paper， fluoroelastomer-based composites were modified with carbon nanotubes， and the effects of carbon nanotube content on the physical properties， thermal properties， microstructure morphology， air permeability， and macroscopic mechanical properties of the modified fluoroelastomer composites were investigated. Aging experiments were conducted for the composites under simulated high-temperature and high-pressure conditions， and their hardness changes， the volume changes， tensile properties， tearing properties and compressive permanent deformation were evaluated and analyzed before and after the aging experiments. The results indicated that the modified fluoroelastomer composites presented an increase in tensile strength and tear strength with increasing the carbon tube content. Based on the observation for the brittle fracture surface and thermal weight loss section， a uniform dispersion of carbon nanotubes was confirmed at their high contents. A network structure was constructed in the composites by carbon nanotubes as a one-dimensional nanomaterial， which contributed to the gas barrier performance of the composites. According to a comparison between the performance data before and after experiments， the introduction of carbon nanotubes maintained the comprehensive properties of the fluoroelastomer composites after the aging experiments.

Key words: carbon nanotubes, fluoroelastomer, thermal stability, microscopic morphology, aging