Membrane technology has shown significant growth during the past two decades in the gas separation industry due to its energy‐savings, compact and modular design, continuous operation, and environmentally benign nature. Robust materials with higher permeability and selectivity are key to reduce capital and operational cost, pushing it forward to replace or debottleneck conventional energy‐intensive unit operations such as distillation. Recently designed ladder polymers of intrinsic microporosity (PIM) and polyimides of intrinsic microporosity (PIM‐PI) with pores <20 Å have demonstrated excellent gas permeation performance. Here, a series of plasticization‐resistant PIM‐based membrane materials is reported, including the first example of a hydroxyl‐functionalized triptycene‐ and Tröger's base‐derived ladder PIM and two PIM‐PI homopolymers and a series of dual‐functionalized polyimide blends containing hydroxyl‐ and carboxyl‐functionalized groups. Specifically, 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA)‐based PIM‐PI blends demonstrated extremely high selectivity for a variety of industrially important applications. An optimized polyimide blend containing ─OH and ─COOH groups showed permselectivity values of 136 for CO2/CH4, 11.4 for O2/N2 and 636 for H2/CH4. Such extreme size‐sieving capabilities are attributed to physical crosslinking induced by strong hydrogen bonding forming tightly structured polymer networks. The study provides a new general strategy for developing plasticization resistant, robust, and highly‐selective PIM‐based membrane materials.

中文翻译：

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具有本征微孔性的羟基官能化聚合物和双官能团共混物，用于基于膜的高性能气体分离


膜技术由于其节能、紧凑和模块化设计、连续运行和环保特性，在过去二十年中在气体分离行业中显示出显着增长。具有更高渗透性和选择性的坚固材料是降低资本和运营成本的关键，推动其向前发展，以取代或消除蒸馏等传统能源密集型装置操作的瓶颈。最近设计的具有 <20 Å 气孔的本征微孔 （PIM） 阶梯聚合物和具有 <20 Å 本征微孔的聚酰亚胺 （PIM-PI） 已表现出优异的气体渗透性能。本文报道了一系列抗塑化的 PIM 基膜材料，包括第一个羟基官能化的三苯和 Tröger 碱衍生的梯形 PIM 和两种 PIM-PI 均聚物以及一系列包含羟基和羧基官能团的双官能化聚酰亚胺共混物。具体来说，基于 4,4′-（六氟异亚基）二苯二甲酸酐 （6FDA） 的 PIM-PI 混合物在各种工业重要应用中表现出极高的选择性。包含 ─OH 和 ─COOH 基团的优化聚酰亚胺共混物显示，CO₂/CH₄ 的渗透选择性值为 136，O₂/N₂ 的渗透选择性值为 11.4，H₂/CH₄ 的渗透选择性值为 636。这种极端的筛分能力归因于强氢键形成结构紧密的聚合物网络所诱导的物理交联。该研究为开发抗塑化、坚固和高选择性的基于 PIM 的膜材料提供了一种新的通用策略。