N,N'-(2,2'-bis(trifluoromethyl)-[1,1'-biphenyl]-4,4'-diyl)bis(4-aminobenzamide), CAS number 1449757-11-2, commonly known as AB-TFMB, has two anilines connecting to a trifluoromethyl biphenyl core through two carboxamides. AB-TFMB is used to synthesize polyimides with high transparency and low linear coefficient of thermal expansion (CTE) which are ideal for flexible displays. The transparency is brought by the trifluoromethyl substituents hindering the intermolecular charge transfer. The low CTE (4.2 ppm/K) is achieved by the linear and rigid structure of AB-TFMB.
The AB-TFMB based polyimides are also gas permeable with O2-transmission rate up to 2313 cm3/m2/day at 23 °C and 1.01 bar.