Microporous aromatic polyimides derived from triptycene-based dianhydride

A novel triptycene-based dianhyride as a shape-persistent building block with high internal free volume was conveniently synthesized via solvothermal method. Subsequently, three all-aromatic polyimides, PIa, PIb and PIc, were prepared by a one-step polycondensation of triptycene-2,3,6,7-tetracarboxylic dianhydride with 2,2′-bis(trifluoromethyl)benzidine, m-tolidine and 3,3′,5,5′-tetramethylbenzidine, respectively. The corresponding polymers exhibit good solubility, excellent thermal stability, significant microporosity with large BET surface areas of up to 623 m2 g−1, as well as an unexpected optical property with a transmittance of ∼85% at 450 nm as ∼20 μm membranes.

Graphical abstractA new aromatic dianhydride of triptycene as a shape-persistent building block with high internal free volume was conveniently synthesized via a solvothermal method and polymerized with diamines to produce polyimides. PIa, PIb and PIc with large BET surface areas up to 623 m2 g−1 are transparent, colorless and completely amorphous and have good thermostability.Figure optionsDownload full-size imageDownload as PowerPoint slide