Synthesis and Gas-Permeation Characterization of a Novel High-Surface Area Polyamide Derived from 1,3,6,8-Tetramethyl-2,7-diaminotriptycene: Towards Polyamides of Intrinsic Microporosity (PIM-PAs)

Polymers

Yingge Wang¹  Giuseppe Genduso²  BaderS. Ghanem²  Ingo Pinnau² 

[1] Advanced Membranes, and Porous Materials Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia;Functional Polymer Membranes Group, Advanced Membranes and Porous Materials Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia;

关键词: triptycene diamine;    glassy polymers;    polyamides;    PIM-polyamides;    gas separation;    mixed-gas permeation;    gas sorption;    intrinsic microporosity;   

DOI  :  10.3390/polym11020361

来源: DOAJ

【 摘 要 】

A triptycene-based diamine, 1,3,6,8-tetramethyl-2,7-diamino-triptycene (TMDAT), was used for the synthesis of a novel solution-processable polyamide obtained via polycondensation reaction with 4,4′-(hexafluoroisopropylidene)bis(benzoic acid) (6FBBA). Molecular simulations confirmed that the tetrasubstitution with ortho-methyl groups in the triptycene building block reduced rotations around the C⁻N bond of the amide group leading to enhanced fractional free volume. Based on N₂ sorption at 77 K, 6FBBA-TMDAT revealed microporosity with a Brunauer⁻Emmett⁻Teller (BET) surface area of 396 m² g⁻¹; to date, this is the highest value reported for a linear polyamide. The aged 6FBBA-TMDAT sample showed moderate pure-gas permeabilities (e.g., 198 barrer for H₂, ~109 for CO₂, and ~25 for O₂) and permselectivities (e.g., αH₂/CH₄ of ~50) that position this polyamide close to the 2008 H₂/CH₄ and H₂/N₂ upper bounds. CO₂⁻CH₄ mixed-gas permeability experiments at 35 °C demonstrated poor plasticization resistance; mixed-gas permselectivity negatively deviated from the pure-gas values likely, due to the enhancement of CH₄ diffusion induced by mixing effects.

【 授权许可】

Unknown