Electrical and mechanical properties of polyimide composite films reinforced by ultralong titanate nanotubes

Ultralong titanate nanotubes (TNs) were successfully synthesized by using hydrothermal method. The TNs were introduced into polyimide (PI) to prepare a kind of promising PI/TNs composite films. The effects of the doping contents on electrical and mechanical properties of the PI/TNs composites were investigated. Results show that the electrical and mechanical properties of the PI/TNs composites are improved remarkably compared to that of the pure PI. With only 0.25 wt% TNs loading, the elongation at break can reach 60.3%, about 235.1% greater than that of the pure PI. In addition, the corona-resistant lifetime of the PI/TNs composite doped with TNs content of 3 wt% improved about ten times higher than the pure PI. The compatibility and interaction between TNs and PI matrix were investigated by the scanning electron microscopy (SEM) and synchrotron radiation small angle X-ray scattering (SAXS). How the microstructure and interface of the PI/TNs composites influence the electrical and mechanical performances was discussed in detail. This study on the PI/TNs composites provides a possibility for realizing a potential application in the high strength insulation devices.