An in situ fabrication process for highly electrical conductive polyimide/MWCNT composite films using 2,6-diaminoanthraquinone

We present a valuable in situ fabrication process for synthesizing high electrical conductive polyimide/multiwalled carbon nanotube (PI/MWCNT) composite films. The success of this process was achieved the addition of 2,6-diaminoanthraquinone (DAAQ). The DAAQ is not only an excellent dispersion agent to stably disperse pristine MWCNTs in solvent but also a monomer to directly synthesize PI. The strong interaction between DAAQ with MWCNT was verified by FTIR, UV-Vis, Raman, and fluorescence spectra. The highest value of electrical conductivity of 55.6 S/cm are achieved by the PI composite containing 40 wt.% of MWCNT. Moreover, the electrical conductivity of this film further enhanced to 106 S/cm after the thermal compression process. The MWCNT content at the percolation threshold of conductivity is 0.50 wt.% (or 0.32 vol.%) and the critical exponent is equal to 2.52. The developed in situ fabrication process through DAAQ-derived molecules can also be applied to synthesize other polymers requiring diamine structure.