Molecularly Engineered Contorted Polyimides: Unraveling the Role of Backbone Rigidity in Gas Separation

Hong-Qin Zhao; Bing-Yu Zou; Bing-Xi He; Wei-Feng Peng; Lu-Hao Qiu; Feng Bao; Ming-Jun Huang; Huan-Yu Lei

doi:10.1007/s10118-025-3530-4

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Molecularly Engineered Contorted Polyimides: Unraveling the Role of Backbone Rigidity in Gas Separation

RESEARCH ARTICLE | Updated：2026-02-13

- Molecularly Engineered Contorted Polyimides: Unraveling the Role of Backbone Rigidity in Gas Separation
- Chinese Journal of Polymer Science Vol. 44, Issue 3, Pages: 733-742(2026)
- Affiliations：
  
  a.School of Emergent Soft Matter, State Key Laboratory of Advanced Papermaking and Paper-based Materials, South China University of Technology, Guangzhou 510640, China
  b.Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
  c.Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials, South China University of Technology, Guangzhou 510640, China
  d.State Key Laboratory of Green and Efficient Development of Phosphorus Resources, Guiyang 550014, China
- Author bio：
  
  huangmj25@scut.edu.cn (M.J.H.)
  leihy@suda.edu.cn (H.Y.L.)
- Funds：
- DOI：10.1007/s10118-025-3530-4
  CLC：
- Received：13 October 2025，
  
  Accepted：09 December 2025，
  
  Online First：02 February 2026，
  
  Published：15 March 2026
- Accepted：
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Zhao, H. Q.; Zou, B. Y.; He, B. X.; Peng, W. F.; Qiu, L. H.; Bao, F.; Huang, M. J.; Lei, H. Y. Molecularly engineered contorted polyimides: unraveling the role of backbone rigidity in gas separation. Chinese J. Polym. Sci. 2026, 44, 733–742

Hong-Qin Zhao, Bing-Yu Zou, Bing-Xi He, et al. Molecularly Engineered Contorted Polyimides: Unraveling the Role of Backbone Rigidity in Gas Separation[J]. Chinese Journal of Polymer Science, 2026, 44(3): 733-742.
Zhao, H. Q.; Zou, B. Y.; He, B. X.; Peng, W. F.; Qiu, L. H.; Bao, F.; Huang, M. J.; Lei, H. Y. Molecularly engineered contorted polyimides: unraveling the role of backbone rigidity in gas separation. Chinese J. Polym. Sci. 2026, 44, 733–742 DOI： 10.1007/s10118-025-3530-4.

Hong-Qin Zhao, Bing-Yu Zou, Bing-Xi He, et al. Molecularly Engineered Contorted Polyimides: Unraveling the Role of Backbone Rigidity in Gas Separation[J]. Chinese Journal of Polymer Science, 2026, 44(3): 733-742. DOI： 10.1007/s10118-025-3530-4.

摘要

Rigid dianhydride–contorted diamine microporous polyimides (PIM-PIs) generate high microporosity and sub-5 Å pores

enabling polyimide membranes with high CO

permeability and selectivity.

Abstract

Microporous polyimides (PIM-PIs) have emerged as promising high-performance membranes for gas separation. However

achieving an optimal balance between permeability and selectivity remains a major challenge. In this study

we designed and synthesized a series of PIM-PIs by combining rigid dianhydrides 9-bis(trifluoromethyl)-2

7-xanthenetetracarboxylic dianhydride (6FCDA) and 4

4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) with contorted diamines

including 9

9-bis(4-aminophenyl)fluorene (FDA)

9′-spirobifluorene-2

2′-diamine (SBFDA)

and 3

3′

3′-tetramethyl-1

1′-spirobiindane-5

5′-diamine-6

6′-diol (TSDA)

to systematically elucidate the relationship between hierarchical microstructure and gas transport behavior. Comprehensive characterization revealed that the 6FCDA-based polymers exhibited a higher microporosity (

micro

total

up to 54.7%) and fractional free volume compared to their 6FDA counterparts. Gas permeation measurements showed that the 6FCDA/SBFDA membrane delivered a CO

permeability of 386 Barrer and CO

/CH

selectivity of 30.2

exceeding the 2008 Robeson upper bound. Structure-property correlation analyses indicated that diffusion selectivity predominantly governed gas separation performance

with rigid

spirocyclic architectures suppressing chain packing to generate sub-5 Å micropores

as further validated by molecular simulations. The optimized 6FCDA/FDA membrane achieved a BET surface area of 423 m

·g

–1

while maintaining excellent mechanical strength and high thermal stability. This work establishes an effective monomer design strategy to overcome the permeability-selectivity trade-off through backbone rigidification

thereby advancing PIM-PIs for practical applications in natural gas purification and carbon capture.

关键词

Keywords

references

Low, Z. X.; Budd, P. M.; McKeown, N. B.; Patterson, D. A. Gas permeation properties, physical aging, and its mitigation in high free volume glassy polymers. Chem. Rev. 2018 , 118 , 5871−5911..

Valappil, R. S. K.; Ghasem, N.; Al-Marzouqi, M. Current and future trends in polymer membrane-based gas separation technology: a comprehensive review. J. Ind. Eng. Chem. 2021 , 98 , 103−129..

Budd, P.; Msayib, K.; Tattershall, C.; Ghanem, B.; Reynolds, K.; McKeown, N.; Fritsch, D. Gas separation membranes from polymers of intrinsic microporosity. J. Membrane Sci. 2005 , 251 , 263−269..

Oh, H. J.; Phillip, W. A. Polymer physics of separation membranes. Macromolecules 2024 , 57 , 9489−9497..

Wang, Z.; Luo, X.; Zhang, J.; Zhang, F.; Fang, W.; Jin, J. Polymer membranes for organic solvent nanofiltration: recent progress, challenges and perspectives. Adv. Membr. 2023 , 3 , 100063..

Liaw, D.; Wang, K.; Huang, Y.; Lee, K.; Lai, J.; Ha, C. Advanced polyimide materials: syntheses, physical properties and applications. Prog. Polym. Sci. 2012 , 37 , 907−974..

Wang, C. Y.; Jiang, C. R.; Yu, B.; Zhao, X. Y.; Cui, Z. L.; Li, J.; Ren, Q. Highly soluble polyimides containing di-tert-butylbenzene and dimethyl groups with good gas separation properties and optical transparency. Chinese J. Polym. Sci. 2020 , 38 , 759−768..

Gan, C. J.; Xu, X. C.; Jiang, X. W.; Gan, F.; Dong, J.; Zhao, X.; Zhang, Q. H. Fabrication of 6FDA-HFBAPP polyimide asymmetric hollow fiber membranes and theirCO 2 /CH 4 separation properties. Chinese J. Polym. Sci. 2019 , 37 , 815−826..

Feng, W. X.; Zhang, S. Q.; Xu, Y. Y.; Ye, X. F.; Xu, X. Y.; Wang, L. Q.; Lin, J. P.; Cai, C. H.; Du, L. Machine-learning-assisted materials genome approach for designing high-performance thermosetting polyimides. Chinese J. Polym. Sci. 2025 , 43 , 1718−1729..

Liu, Z.; Liu, Y.; Qiu, W.; Koros, W. J. Molecularly engineered 6FDA-based polyimide membranes for sour natural gas separation. Angew. Chem. Int. Ed. 2020 , 59 , 14877−14883..

Sanaeepur, H.; Ebadi Amooghin, A.; Bandehali, S.; Moghadassi, A.; Matsuura, T.; Van der Bruggen, B. Polyimides in membrane gas separation: monomer’s molecular design and structural engineering. Prog. Polym. Sci. 2019 , 91 , 80−125..

Liu, Z.; Qiu, W.; Quan, W.; Koros, W. J. Advanced carbon molecular sieve membranes derived from molecularly engineered cross-linkable copolyimide for gas separations. Nat. Mater. 2023 , 22 , 109−116..

Ye, C.; Luo, C.; Ji, W.; Weng, Y.; Li, J.; Yi, S.; Ma, X. Significantly enhanced gas separation properties of microporous membranes by precisely tailoring their ultra-microporosity through bromination/debromination. Chem. Eng. J. 2023 , 451 , 138513..

Zhuang, Y.; Seong, J. G.; Lee, Y. M. Polyimides containing aliphatic/alicyclic segments in the main chains. Prog. Polym. Sci. 2019 , 92 , 35−88..

Yang, W.; Yuan, L.; Gong, K.; Zhang, R.-H.; Lei, L.; Li, H. Methyl groups pendant on triphenylmethane toward modulating thermal stability and dielectric properties of the crosslinkable fluorinated polyimide films with high transparency. Chinese J. Polym. Sci. 2025 , 43 , 316−327..

Jia, Y.; Zhai, L.; Mo, S.; Liu, Y.; Liu, L.-X.; Du, X.-Y.; He, M.-H.; Fan, L. Effect of low-temperature imidization on properties and aggregation structures of polyimide films with different rigidity. Chinese J. Polym. Sci. 2024 , 42 , 1134−1146..

Tong, X.; Wang, S.; Dai, J.; Wang, S.; Zhang, K.; Zhao, X.; Wang, D.; Chen, C. The effect of chain rigidity and microstructure on gas separation performance of the cardo-based polyimides. Polymer 2022 , 254 , 125046..

Zou, B. Y.; Qiu, L. H.; Lei, H. Y.; Liu, J. M.; Peng, W. F.; Zhao, H. Q.; Bao, F.; Huang, M. J. Fluorinated colorless polyimides with high heat-resistance and low birefringence. Chinese J. Polym. Sci. 2023 , 41 , 1599−1608..

Bao, F.; Qiu, L.; Zou, B.; Lei, H.; Peng, W.; Cheng, S. Z. D.; Huang, M. Development of fluorinated colorless polyimides of restricted dihedral rotation toward flexible substrates with thermal robustness. Macromolecules 2024 , 57 , 3568−3579..

Qiu, L.; Peng, W.; Zou, B.; He, B.; Bao, F.; Lei, H.; Huang, M. Comprehensive advantages of colorless, transparent, and thermally stable aromatic polyimides via fluorinated terphenyl dianhydride. Polymer 2025 , 334 , 128741..

Bezzu, C. G.; Carta, M.; Ferrari, M. C.; Jansen, J. C.; Monteleone, M.; Esposito, E.; Fuoco, A.; Hart, K.; Liyana-Arachchi, T. P.; Colina, C. M.; McKeown, N. B. The synthesis, chain-packing simulation and long-term gas permeability of highly selective spirobifluorene-based polymers of intrinsic microporosity. J. Mater. Chem. A 2018 , 6 , 10507−10514..

Ma, X.; Salinas, O.; Litwiller, E.; Pinnau, I. Novel spirobifluorene- and dibromospirobifluorene-based polyimides of intrinsic microporosity for gas separation applications. Macromolecules 2013 , 46 , 9618−9624..

Hayek, A.; Alsamah, A.; Saleem, Q.; Alhajry, R. H.; Alsuwailem, A. A. Enhanced H 2 S and CO 2 selectivities through bromo-substitution of polyimide membranes for sour natural gas up grading. J. Membr. Sci. 2025 , 721 , 123807..

Lu, Y.; Guo, H.; Cai, M.; Ma, X.; Wang, Z.; Yan, J. Systematic investigation of microstructures and gas separation performance of thermally rearranged polybenzoxazole membranes derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride. Macromolecules 2024 , 57 , 9877−9888..

Zheng, Z.; Zhang, M.; Wen, Y.; Wang, Z.; Yan, J. Synthesis and gas separation performance of intrinsically microporous polyimides derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride. Eur. Polym. J. 2025 , 239 , 114301..

Tan, W. Y.; Jian, L. F.; Chen, W. P.; Zhang, Y. W.; Lu, X. C.; Huang, W. J.; Zhang, J. S.; Wu, J. W.; Feng, J. L.; Liu, Y. D.; Cui, T. T.; Min, Y. G. A facile strategy for intrinsic low-dk and low-df polyimides enabled by spirobifluorene groups. Chinese J. Polym. Sci. 2022 , 41 , 288−296..

Chen, H.; Dai, F.; Wang, M.; Ke, Z.; Yan, K.; Li, D.; Chen, C.; Qian, G.; Yu, Y. Synthesis, characterization and properties of polyimides with spirobisbenzoxazole scaffold structure. Polymer 2022 , 254 , 125091..

Wang, G.; Zhang, Y.; Huang, Y.; Wang, Y.; Li, K.; Jiao, L.; Chen, Z.; Niu, Z.; Guo, M.; Yang, L.; Cheng, B. Anchoring the dianhydride structure to simultaneously enhance the permeability and selectivity of the polybenzoxazole membranes. Macromolecules 2025 , 58 , 3255−3266..

Ma, X.; Swaidan, R.; Belmabkhout, Y.; Zhu, Y.; Litwiller, E.; Jouiad, M.; Pinnau, I.; Han, Y. Synthesis and gas transport properties of hydroxyl-functionalized polyimides with intrinsic microporosity. Macromolecules 2012 , 45 , 3841−3849..

Huang, Y.; Li, K.; Zhang, Y.; Wang, G.; Ma, Y.; Jiao, L.; Shu, D.; Yang, S.; Ma, X.; Zhang, Q.; Yang, L.; Cheng, B. Fine-tuning gas separation performance of copolymer polyimide by the regulation of local microstructure. J. Membr. Sci. 2025 , 718 , 123689..

Chen, H.; Dai, F.; Wang, M.; Yan, X.; Ke, Z.; Chen, C.; Qian, G.; Yu, Y. Preparation and gas separation properties of spirobisbenzoxazole-based polyimides. Eur. Polym. J. 2022 , 173 , 111231..

Zhuang, Y.; Seong, J. G.; Do, Y. S.; Jo, H. J.; Cui, Z.; Lee, J.; Lee, Y. M.; Guiver, M. D. Intrinsically microporous soluble polyimides incorporating tröger’s base for me mbrane gas separation. Macromolecules 2014 , 47 , 3254−3262..

Hu, X.; Miao, J.; Pang, Y.; Zhao, J.; Lu, Y.; Guo, H.; Wang, Z.; Yan, J. Synthesis, microstructures, and gas separation performance of norbornyl bis-benzocyclobutene-Tröger's base polymers derived from pure regioisomers. Polym. Chem. 2022 , 13 , 2842−2849..

Zhang, Y.; Lee, W. H.; Seong, J. G.; Dai, J.; Feng, S.; Wan, Y.; Lee, Y. M.; Zhuang, Y. Effect of structural isomerism on physical and gas transport properties of Tröger's Base-based polyimides. Polymer 2022 , 239 , 124412..

Guo, H.; Hu, X.; Zheng, T.; Wang, Z.; Yan, J. Synthesis and gas separation performance of Tröger's base-containing polyimides derived from 9,9-Bis(trifluoromethyl)-2,3,6,7-xanthenetetracarboxylic dianhydride. Eur. Polym. J. 2023 , 193 , 112100..

Wang, Y.; Alaslai, N.; Ghanem, B.; Ma, X.; Hu, X.; Balcik, M.; Liu, Q.; Abdulhamid, M. A.; Han, Y.; Eddaoudi, M.; Pinnau, I. Hydroxyl-functionalized polymers of intrinsic microporosity and dual-functionalized blends for high-performance membrane-based gas separations. Adv. Mater. 2024 , 36 , 2406076..

Guo, W.; Sun,L.; Chu, J.; Liu, L.; Li, J.; Ma, X. Huge improved gas separation performance of carbon molecular sieve membrane by forming a double crosslinked polyimide precursor. J. Membr. Sci. 2024 , 711 , 123218..

Yerzhankyzy, A.; Ghanem, B. S.; Wang, Y.; Alaslai, N.; Pinnau, I. Gas separation performance and mechanical properties of thermally-rearranged polybenzoxazoles derived from an intrinsically microporous dihydroxyl-functionalized triptycene diamine-based polyimide. J. Membr. Sci. 2020 , 595 , 117512..

Hu, X.; Mu, H.; Miao, J.; Lu, Y.; Wang, X.; Meng, X.; Wang, Z.; Yan, J. Synthesis and gas separation performance of intrinsically microporous polyimides derived from sterically hindered binaphthalenetetracarboxylic dianhydride. Polym. Chem. 2020 , 11 , 4172−4179..

Wang, M.; Liao, J.; Gao, C.; Ma, J.; Meng, X.; Shen, Y.; Wu, X.; Wang, Y.; Li, J. A novel approach to synthesizing Trimesoylchloride-branched 6FDA-based polyimide membranes with superior stability for high-performance gas separation. J. Membr. Sci. 2025 , 720 , 123713..

Ma, J.; He, W.; Lim, W.; Du, J.; Sun, Q.; Hassan, S. U.; Cao, D.; Guan, J.; Liu, J. Finely tailoring microstructure of hyperbranched polyimide membrane for facile natural gas upgrading. J. Membrane Sci. 2025 , 720 , 123729..

Huang, L. J.; Weng, Y. T.; Raiz, A.; Mao, Z. J.; Ma, X. H. Remarkably improved gas separation performance of polyimides by forming “bent and battered” main chain using paracyclophane as building block. Chinese J. Polym. Sci. 2023 , 41 , 1617−1628..

Suzuki, T.; Miki, M.; Yamada, Y. Gas transport properties of hyperbranched polyimide/hydroxypolyimide blend membranes. Eur. Polym. J. 2012 , 48 , 1504−1512..

Zhang, Z.; Ren, X.; Huo, G.; Kang, S.; Wang, Z.; Li, N. Tuning interchain cavity of fluorinated polyimide by DABA for improved gas separation performance. J. Membrane Sci. 2023 , 675 , 121485..

Luo, X.; Wang, Z.; Wu, S.; Fang, W.; Jin, J. Metal ion cross-linked nanoporous polymeric membranes with improved organic solvent resistance for molecular separation. J. Membr. Sci. 2021 , 621 , 119002..

Niu, C.; Zhao, G.; Chen, B.; Tang, G.; Liu, Y.; Li, P. Fabrication of Ester cross-linked phenolphthalin-based polyimides for gas separations. J. Membrane Sci. 2025 , 719 , 123715..

Ren, Z.; Zhao, G.; Wang, F.; Chen, B.; Tang, G.; Liu, Y.; Li, P. Synthesis of an o-cresolphthalein-based polyimide and its derivative cross-linked thermally rearranged polymers for gas separation. Macromolecules 2025 , 58 , 733−743..

Zhao, W.; Zhang, J.; Liu, C.; Ma, Y.; Li, K.; Guo, M.; Jiao, L.; Ma, X.; Yang, L.; Yang, S.; Cheng, B. Fine-tuning gas separation performance of intrinsic microporous polyimide by the regulation of atomic-level halogen substitution. J. Membrane Sci. 2024 , 692 , 122317..

Lei, H.; Li, X.; Wang, J.; Song, Y.; Tian, G.; Huang, M.; Wu, D. DFT and molecular dynamic simulation for the dielectric property analysis of polyimides. Chem. Phys. Lett. 2022 , 786 , 139131..

Peng, W.; Lei, H.; Zou, B.; Qiu, L.; Song, Y.; Huang, X.; Ye, F.; Bao, F.; Huang, M. Fluorine atom substituted aromatic polyimides: unlocking extraordinary dielectric performance and comprehensive advantages. Giant 2024 , 18 , 100262..

Lei, H.; Bao, F.; Peng, W.; Qiu, L.; Zou, B.; Huang, M. Torsion effect of the imide ring on the performance of transparent polyimide films with methyl-substituted phenylenediamine. Polym. Chem. 2022 , 13 , 6606−6613..

Peng, W.; Lei, H.; Zhang, X.; Qiu, L.; Huang, M. Fluorine substitution effect on the material properties in transparent aromatic polyimides. Chinese J. Polym. Sci. 2022 , 40 , 781−788..

Wakita, J.; Jin, S.; Shin, T. J.; Ree, M.; Ando, S. Analysis of molecular aggregation structures of fully aromatic and semialiphatic polyimide films with synchrotron grazing incidence wide-angle x-ray scattering. Macromolecules 2010 , 43 , 1930−1941..

Lei, H.; Tian, G.; Xiao, M.; Li, X.; Qi, S.; Wu, D. Application of molecular simulation in the study of polyimide. Acta Polymerica Sinica (in Chinese) 2019 , 50 , 1253−1262..

Lei, H.; Qi, S.; Wu, D. Hierarchical multiscale analysis of polyimide films by molecular dynamics simulation: investigation of thermo-mechanical properties. Polymer 2019 , 179 , 121645..

Lu, T.; Chen, F. Multiwfn: a multifunctional wavefunction analyzer. J. Comput. Chem. 2012 , 33 , 580−592..

Zhang, C.; Li, P.; Cao, B. Effects of the side groups of the spirobichroman-based diamines on the chain packing and gas separation properties of the polyimides. J. Membrane Sci. 2017 , 530 , 176−184..

Zhao, W.; Li, K.; Ma, Y.; Gao, Y.; Zhang, J.; Zhou, L.; Wang, W.; Wang, J.; Ma, Y.; Guo, M.; Yang, L.; Ma, X.; Cheng, B. Simultaneously enhanced gas separation and anti-aging performance of intrinsic microporous polyimide by dibromo substitution. J. Membr. Sci. 2023 , 687 , 122081..

Maya, E. M.; García-Yoldi, I.; Lozano, A. E.; de la Campa, J. G.; de Abajo, J. Synthesis, characterization, and gas separation properties of novel copolyimides containing adamantyl ester pendant groups. Macromolecules 2011 , 44 , 2780−2790..

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