Preparation of novel fluorinated highly branched (A3 + B3)‐type hyperbranched poly(amide‐imides) for electrochromism and iodine adsorption

Abstract

AbstractIn this study, a series of (A3 + B3)‐type fluorinated hyperbranched poly(amide‐imides) were successfully synthesized with carbazole and fluorene units as end‐capping moieties. All synthesized end‐capping hyperbranched PAIs showed over 70% branching as determined by 1H NMR, demonstrating good solubility and thermal stability (Tgs: 242–263°C, T10%: 576–629°C). The HOMO and LUMO energy levels of hyperbranched PAI films were measured at 4.65–4.73 and 1.51–1.66 eV, respectively, suggesting favorable reoxidation and reduction characteristics. PAI‐2 demonstrates a 46.6% transmittance variation (∆T, 418 nm), along with a coloring/bleaching process time of 2.3 s/1.6 s, a coloring efficiency (CE) of 310 cm2/C, and exceptional redox stability over 100 cycles. Furthermore, the synthesized PAIs containing electron‐withdrawing groups exhibited a high iodine adsorption capacity as determined by iodine adsorption tests (PAI‐1: 534 mg/g, PAI‐2: 579 mg/g, PAI‐3: 490 mg/g).