Multi-Walled Carbon Nanotube Reinforced Polyimide Composites

Abstract

Polyimides have a wide range of uses such as aeronautical applications of fuelcells, optics and electronic materials industry due to their outstanding thermal,mechanical and chemical properties. In this study, it was aimed to prepare compositepolyimide films with amine-tethered multi-walled-carbon nanotubes (MWCNT). Firstly, toproduce amine functional groups onto the surface of MWNCTs, MWCNTs were reactedwith H2SO4/HNO3, thionyl chloride and ethylenediamine. Then polyamic acid solution wasprepared from 3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) and, 4′-oxydianiline (ODA). The functionalized carbon nanotube was added to the PAA solutionswith certain amounts (1, 3, 4, 5 and 6 wt. % followed by stepwise thermal imidization.The thermal stability of the composite polyimide films were enhanced with addition ofmodified-carbon nanotube due to covalent interaction between polyimide based matrixand modified-carbon nanotube as a result of the imidization reaction. The addition ofMWCNT increased the Tg of the BTDA-ODA-6% MWCNTs polymide film from 275 to 304°C with respect to the BTDA-ODA polyimide film. In addition, the mechanical propertiesof the films were improved. While the modulus of BTDA-ODA film was found as 743 MPa,with the introduction of MWCNT the modulus of BTDA-ODA-6% MWCNTs was increasedup to 1119 MPa.