Synthesis And Properties Of Poly(Amic Acid) Containing Oligoaniline Segments

As an important conductive polymer, PANI has received extensive attentions andresearch due to its easy synthesis, good environment stability, reversible redox,reversible acid/base doping/dedoping chemistry, which shows a wide range ofpromising applications in the field of anticorrosive coatings, electrochromic materials,microwave absorbing materials, et al. However, PANI usually exhibits someproblems, such as the ill-defined molecular structure, infusibility, the poor processingperformance, which limits its practical application. In contrast to PANI, oligoanilineis drawing more attention due to its regular structure, good solubility, excellentlyelectrical and optical properties. However, their bad mechanical properties, poorfilm-formation and bad stability make them impossible for application.In this work, we focus on to improve the solubility and processing performanceof PANI. We introduced the oligoaniline as the side chain of poly(amic acid), whichutilized the oligoaniline and poly(amic acid) to obtain some new properties.First, we reported the synthesis of a new self-doped poly(amic acid) containingoligoaniline, azobenzene groups and sulfonic acid groups. The prepared polymershowed good solubility and excellent thermal stability. Based on the existence ofsulfonic acid and carboxylic acid groups, the polymer exhibits excellent electroactivtyin acid, neutral and even alkaline solutions. Moreover, due to the synergistic effect of the three different groups, the polymer revealed acceptable electrochromicperformance even in neutral and alkaline solutions and multicolor with the changingof pH and applied potential.Second, we described the synthesis of a novel electroactive poly(amic acid)containing oligoaniline pendants by one-step polycondensation. The obtained polymershows good solubility, reversible electroactivity, and good electrochromicperformance due to the existence of oligoaniline as the pendants. Moreover, due to thereversible acid–base doping–dedoping properties, the EPAA nanofibers exhibitacceptable gas sensing properties towards ammonia.Finally, we have synthesized a novel polymer with oligoaniline pendants thatexhibits good solubility, electroactivity and electrochromic properties. We haveshown that multistimuli-responsive fluorescence switching behavior can be performedon this polymer by chemical, pH, and electrical potential stimuli. Though thefluorescence switching was not entirely satisfactory, it demonstrated the availabilityof controlling/adjusting the fluorescence of polymers through a variety of inputs.