Silane Modified Multiwall Carbon Nanotubes/Polyimide Composites Prepared Using In-Situ Polymerization

In this study, multiwall carbon nanotubes (MWNTs) were modified with a mixture of acids (H₂SO₄/HNO₃), and subsequently functionalized with a coupling agent, 3-aminopropyltriethoxysilane (APTES). Silanization was performed for 2, 4, and 6 h in a reflux apparatus. The functionalized MWNTs were examined using energy dispersive spectroscopy analysis (EDS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy, and thermogravimetric analysis (TGA). The results showed that APTES successfully attached to the MWNTs. In-situ polymerization of polyimide (PI) enhanced the dispersion and compatibility of the MWNTs with PI, as well as the electrical conductivity, and the thermal and mechanical properties of the PI/MWNT nanocomposites. Electrical conductivity reached 2.59 × 10⁷ Ω/cm² when the PI nanocomposites were loaded with 2 wt% AP-CNTs after 2 h silanization, which met the criterion for electrostatic charge mitigation (10⁶–10⁸ Ω/cm²).