Surfactant-Modified MWNT/Polyimide Composites by In Situ Polymerization

In this study, we attempted to enhance the electrical conductivity and mechanical properties of polyimide (PI) using non-covalently modified multiwall carbon nanotubes (MWNTs). The MWNTs were first oxidized (o-CNT) and modified with nitric acid (n-CNT). The o-CNT and n-CNT were then modified with an anionic surfactant (Sodium dodecylbenzenesulfonate) (SDBS) to improve their dispersion in the PI matrix. We also examined the properties of the surfactant-modified MWNTs prepared by filtration or centrifugation. The MWNTs prepared by centrifugation exhibited better dispersion in the PI matrix. We confirmed the successful preparation of the surfactant-modified MWNTs by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and UV visible spectroscopy. The results of this study further show that in-situ polymerization can increase the thermal stability, electrical properties and mechanical properties of PI/MWNT nanocomposites.