Microporous Polyimides with Rationally Designed Chain Structure Achieving High Performance for Gas Separation

Abstract

Polyimides of intrinsic microporosity are important polymers for gas separation. Achieving polyimides with high permeability and high selectivity relies on rationally designing their chain structure. In this work, new ladder-like diamines, Tröger’s Base (TB) derived diamines, are designed, and two microporous polyimides are constructed by polymerizing TB-derived diamines and spirobisindane based dianhydride, aiming at enhancing the stiffness of the whole backbone and thus achieving improved performance by taking advantage of the stiffness of both diamines and dianhydride. The two polyimides present excellent separation performance, surpassing the 2008 Robeson upper bound for gas pairs of H2/N2 and O2/N2 and approach the 2008 Robeson upper bound for gas pairs H2/CH4 and CO2/CH4. Our results show that the designed polyimides have great potential for application especially for oxygen (O2/N2) and hydrogen (such as H2/N2 and H2/CH4) related separation.

Effect of methanol treatment on gas sorption and transport behavior of intrinsically microporous polyimide membranes incorporating Tröger׳s base

“…The more rigid EA or TB units in the PIM-EA-TB restrict minor chain flexing, which occurs to a small extent in conventional PIM-1 in both the fused-ring dibenzodioxane and contorted spiro-center structural units. Thus, we and others have incorporated TB units into soluble polyimides to investigate intrinsically microporous polyimides in order to integrate the advantages of the high performance derived from the TB units along with the excellent -5 -physical properties of PIs [31][32][33]. The resulting PI-TB polymers possess good mechanical properties as well as a high FFV and very good gas transport properties compared to conventional PIs.…”

Carbon Molecular Sieve Membranes Derived from Tröger's Base‐Based Microporous Polyimide for Gas Separation

“…Trçger's base (TB), 2,8-dimethyl-6H,12H-5,11-methanodibenzo[b,f] [1,5]diazocine, is constructed by ab ridged bicyclic amine. [39][40][41][42][43][44][45] Therefore, there is great confidence to expect that aT B-containing polymerw ould be ap romising precursor for CMS membranes. [36][37][38] Recently,t he TB unit was used to prepare TB-PIMs to replacethe spirobisindane unit that was mostly used as parto f the polymer backboneo fP IMs.…”

Gas permeation and physical aging properties of iptycene diamine-based microporous polyimides

“…One class of PIMs is based on high-free-volume aromatic polyimides (PIM-PIs) that contain rigid contortion sites either in their dianhydride and/or diamine moiety. Examples of such molecular building blocks are: (i) spirobisindane dianhydrides [7,12,13] and diamines [14,15], ethanoanthracene dianhydride [6,16], spirobifluororene dianhydride [17] and diamines [18,19], Tröger's base diamines [20][21][22], and triptycene dianhydrides [10,23] and diamines [15,24,25].…”