Intrinsically Microporous Polyimides Derived from 2,2'-Dibromo-4,4',5,5'-bipohenyltetracarboxylic Dianhydride for Gas Separation Membranes

Yongle Li; Yao Lu; Chun Tian; Zhen Wang; Jingling Yan

doi:10.3390/polym16091198

Intrinsically Microporous Polyimides Derived from 2,2'-Dibromo-4,4',5,5'-bipohenyltetracarboxylic Dianhydride for Gas Separation Membranes

Polymers (Basel). 2024 Apr 25;16(9):1198. doi: 10.3390/polym16091198.

Authors

Yongle Li^{1

2}, Yao Lu³, Chun Tian¹, Zhen Wang¹, Jingling Yan¹

Affiliations

¹ Ningbo Institute of Material Technology & Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
² College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
³ School of Fine Arts, Zhengzhou University, Zhengzhou 450001, China.

Abstract

This work aims to expand the structure-property relationships of bromo-containing polyimides and the influence of bromine atoms on the gas separation properties of such materials. A series of intrinsically microporous polyimides were synthesized from 2,2'-dibromo-4,4',5,5'-bipohenyltetracarboxylic dianhydride (Br-BPDA) and five bulky diamines, (7,7'-(mesitylmethylene)bis(8-methyldibenzo[b,e][1,4]dioxin-2-amine) (MMBMA), 7,7'-(Mesitylmethylene)bis(1,8-dimethyldibenzo[b,e][1,4] dioxin-2-amine) (MMBDA), 4,10-dimethyl-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine-2,8-diamine (TBDA1), 4,10-dimethyl-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine-3,9-diamine (TBDA2), and (9R,10R)-9,10-dihydro-9,10-[1,2]benzenoanthracene-2,6-diamine (DAT). The Br-BPDA-derived polyimides exhibited excellent solubility, high thermal stability, and good mechanical properties, with their tensile strength and modulus being 59.2-109.3 MPa and 1.8-2.2 GPa, respectively. The fractional free volumes (FFVs) and surface areas (S_BET) of the Br-BPDA-derived polyimides were in the range of 0.169-0.216 and 211-342 m² g^-1, following the order of MMBDA > MMBMA > TBDA2 > DAT > TBDA1, wherein the Br-BPDA-MMBDA exhibited the highest S_BET and FFV and thus highest CO₂ permeability of 724.5 Barrer. Moreover, Br-BPDA-DAT displayed the best gas separation performance, with CO₂, H₂, O₂, N₂, and CH₄ permeabilities of 349.8, 384.4, 69.8, 16.3, and 19.7 Barrer, and H₂/N₂ selectivity of 21.4. This can be ascribed to the ultra-micropores (<0.7 nm) caused by the high rigidity of Br-BPDA-DAT. In addition, all the bromo-containing polymers of intrinsic microporosity membranes exhibited excellent resistance to physical ageing.

Keywords: 2,2′-dibromo-4,4′,5,5′-bipohenyltetracarboxylic dianhydride; PIM-PIs; bromo group; gas separation performance; interchain distances.

Grants and funding

This research was funded by the National Key R&D Program of China (2023YFB3709700), the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang (No. 2021R01005), and the Key Technical Development Program of Ningbo (2021Z091), whom we thank for the financial support.