Triphenylamine‐Based Porous Organic Polymers with High Porosity: their High Carbon‐Dioxide Adsorption and Proton‐Conductivity Emergence

Amorphous porous organic polymers ( POP s) feature high specific surface area and chemical and thermal stability; therefore, they are applied in various fields. It is previously reported that chemical polymerization using iodine as an oxidant enables the synthesis of amorphous POP s without impurities. In this study, an iodine‐based chemical polymerization method is employed to maximize the specific surface area of polytriphenylamine, a typical amorphous POP . Furthermore, 1,3,5‐tris[4‐(diphenylamino)phenyl]benzene, a monomer with three triphenylamine moieties connected by a benzene core, is used to increase the number of reaction points and construct a rigid structure. The resulting poly[1,3,5‐tris[4‐(diphenylamino)phenyl]benzene] ( pTTPA ) exhibited a high specific surface area. Using 200 equivalents of iodine resulted in a pTTPA with the largest Brunauer–Emmett–Teller ( BET ) specific surface area (2134.6 m 2 g −1 ) among previously reported triphenylamine‐based amorphous POP s, and demonstrated a high CO 2 adsorption capacity (3.31 mmol g −1 at 25 °C). Furthermore, pTTPA exhibited significant water–vapor adsorption when the BET specific surface area reached 1500 m 2 g −1 , leading to the emergence of proton conductivity (e.g., 4.33 × 10 −6 S cm −1 at 95% RH and 90 °C). The findings demonstrate that iodine‐based chemical polymerization enables the maximization of the porosity of amorphous POP s and the development of proton conductivity within them.