Abstract
A simple synthetic route to a novel sterically hindered triptycene-based diamine, 1,3,6,8-tetramethy1-2,7 diamnotriptycene (TMDAT), and its use in the preparation of high molecular weight polyimides of intrinsic microporosity (PIM-PIs) are reported. The organosoluble TMDAT-derived polyimides displayed high Brunauer Emmett Teller surface areas ranging between 610 and 850 m(2) g(-1)- and demonstrated excellent thermal stability of up to 510 degrees C. Introduction of the rigid three-dimensional paddlewheel tript7cene framework and the tetramethyl-induced restriction of the imide bond rotation resulted in highly permeable polyimides with moderate gas-pair selectivity. The best performing polyimide made from TMDAT and a triptycene-based dianhydride showed gas transport properties located between the 2008 and 2015 polymer permeability/selectivity trade=off curves with O-2 and O-2 permeabidities of 2858 and 575 barrer combined with H-2/N-2 andO(2)/N-2 selectivities of 24 and 4.8,respectively,after 200 days of physical aging.