Abstract: Polymers of intrinsic microporosity (PIMs) have excellent gas separation performance, but their low flux and poor solubility limit their application in industry. A kind of triptycene polyamide (T-PI) with intrinsic microporosity was prepared by polycondensation of triptycene-2,3,6,7-tetracarboxylic tridietene dianhydride monomer with 2,2-bis (trifluoromethyl) benzidine. The introduction of triphene group makes T-PI soluble in many common organic reagents and has good thermal stability. The permeability for H₂ and CO₂ was 518 and 810 barrer respectively, and the ideal selectivity of CO₂/CH₄ reached 21.9, which was close to Robeson's upper limit of gas separation (2008). The T-PI membrane was used for the separation of H₂ and five light hydrocarbon mixtures. The volume fraction of H₂ was increased from 32.9% to 73.7% by T-PI membrane at 0.4 MPa pressure difference, it showed that the T-PI membrane had a potential to realize separation of H₂ and light hydrocarbon at a low pressure difference.

Key words: triptycene, polyamide, H₂/light hydrocarbon separation, gas separation