Construction of Aniline Trimer Based Conjugated Polymers through Schiff Base Reaction and Their Use as Feedstock for Infrared Stealth Coatings

In order to meet the demand for infrared stealth materials in the military field, conjugated polymers containing Schiff base moieties were designed and prepared. Various dialdehyde monomers were introduced and their effect on the comprehensive properties were systematically characterized. The resulted polymers could be cast in solution to prepare polymer coatings. The coatings exhibited high thermal stability up to 400 degrees C at 5% weight loss, and excellent mechanical performance with high Young's modulus and hardness. The infrared emissivity values varied from 0.587 to 0.627 at wavelength of 8-14 mu m and ranged from 0.595 to 0.609 at wavelength of 2-22 mu m. Specifically, it was found that the ATTPAL structure with carbazole moieties had a lower band gap and better electrical conductivity by photoelectric test and DFT theoretical analysis. Meanwhile, the infrared emissivity value of ATTPAL coating was the lowest compared with p-phenyl and pyridyl containing analogues, suggesting it was potential material for the future development of infrared stealth technology. The combined results showed that reducing the band gap and improving the electrical conductivity of the structure were both beneficial to the reduction of infrared emissivity. It would positively provide new ideas for the design of infrared stealth materials.

Automated summary

In this study, conjugated polymers containing Schiff base moieties were designed and prepared to meet the demand for infrared stealth materials in the military field. The resulting polymers exhibited high thermal stability, excellent mechanical performance, and low infrared emissivity. By modifying the band gap and electrical conductivity of the structure, further reduction of infrared emissivity was achieved, providing new ideas for the design of infrared stealth materials.