Enhancing the Gas Permeability of Troger's Base Derived Polyimides of Intrinsic Microporosity
A series of four novel Troger's base (TB) derived polyimides of intrinsic microporosity (PIM TB PI) is reported. The TB diamine monomer (4MTBDA) possesses four methyl groups in order to restrict rotation about the C N imide bonds in the resulting polymers. The polymers possess apparent BET (Brunauer, Emmett, and Teller) surface areas between 584 and 739 m2 g 1, complete solubility in chloroform, excellent molecular mass, high inherent viscosity and good film forming properties. Gas permeability measurements demonstrate enhanced performance over previously reported polyimide based Troger's base (TB) polymers confirming the benefit of the additional methyl groups within the TB diamine monomer. Notably, a polyimide derived from 4MTBDA and pyromellitic anhydride (PMDA) demonstrates gas permeability data above the 2008 upper bounds for important gas pairs such as O2/N2, H2/N2, and H2/CH4.