Fabrication of PTCA-PANI composites for electromagnetic wave absorption and corrosion protection

The composites of 3,4,9,10-perylene tetracarboxylic acid doped polyaniline (PTCA-PANI) have been successfully fabricated by oxidative polymerization method in hydrochloric acid solution. FTIR, SEM and XRD were employed to characterize the composition, morphology and structure of PTCA-PANI composites. Thermalgravimetric analysis results showed that PTCA-PANI composites had better thermal stability than PANI. The microwave absorption performance of the obtained composites was evaluated by measuring the reflection loss (RL) values. The widest absorption bandwidth of the optimal PTCA-PANI (PTCA-PANI04) composites could reach to 4.4 GHz (11.9–16.3 GHz) at the absorber thickness of 2.0 mm, while the minimum RL was −27.8 dB. And the absorbing frequency could be regulated in the range of 3.8–18 GHz by adjusting the absorber thickness. Furthermore, the corrosion protection performances of the prepared materials incorporated epoxy coatings were investigated by electrochemical impedance spectroscopy and potentiodynamic polarization. The results indicated that PTCA-PANI04 incorporated coating displayed a long-term excellent anti-corrosion efficiency, which was 99.98% after 15 days' immersion in 3.5% NaCl solution, owing to the passivation and barrier effects of PTCA-PANI04 composites. This work can provide a reference for the development of new materials with electromagnetic shielding and corrosion protection dual-function.