Polymers with Side Chain Porosity for Ultrapermeable and Plasticization Resistant Materials for Gas Separations
Polymers with Side Chain Porosity for Ultrapermeable and Plasticization Resistant Materials for Gas Separations
复制标题
DOI：
10.1002/adma.201807871
复制
发表时间：
2019-05-01
影响因子：
29.4
通讯作者：
Smith, Zachary P.
中科院分区：
文献类型：
--
作者：
He, Yuan;Benedetti, Francesco M.;Smith, Zachary P.
需要具有高CO2渗透性和高选择性的聚合物膜来解决与能源和环境相关的一些关键分离挑战，特别是在天然气净化和燃烧后碳捕获中。然而，目前已知很少有可溶液加工的线性聚合物获得这些类型的特征，并且所有已知的结构都通过设计刚性主链化学来实现其分离性能，所述刚性主链化学同时增加链刚度和链间间距，从而导致固态链缠结膜中的超微孔性。本文报道了通过开环易位聚合得到的多孔聚合物的分离性能，该多孔聚合物具有柔性主链和刚性氟化侧链。该聚合物具有良好的CO2渗透性（> 21000 Barrer）和优异的抗塑化性（CO2塑化压力> 51 bar）。与固有微孔性的传统聚合物相比，物理老化的速率较慢，特别是对于具有小有效直径的气体（即，He，H-2和O-2）。这种结构设计策略，再加上对聚合物的研究，展示了一种可推广的方法来创建具有柔性主链和成孔侧链的新聚合物，这些聚合物具有未开发的小分子分离前景。
Polymer membranes with ultrahigh CO2 permeabilities and high selectivities are needed to address some of the critical separation challenges related to energy and the environment, especially in natural gas purification and postcombustion carbon capture. However, very few solution-processable, linear polymers are known today that access these types of characteristics, and all of the known structures achieve their separation performance through the design of rigid backbone chemistries that concomitantly increase chain stiffness and interchain spacing, thereby resulting in ultramicroporosity in solid-state chain-entangled films. Herein, the separation performance of a porous polymer obtained via ring-opening metathesis polymerization is reported, which possesses a flexible backbone with rigid, fluorinated side chains. This polymer exhibits ultrahigh CO2 permeability (>21 000 Barrer) and exceptional plasticization resistance (CO2 plasticization pressure > 51 bar). Compared to traditional polymers of intrinsic microporosity, the rate of physical aging is slower, especially for gases with small effective diameters (i.e., He, H-2, and O-2). This structural design strategy, coupled with studies on fluorination, demonstrates a generalizable approach to create new polymers with flexible backbones and pore-forming side chains that have unexplored promise for small-molecule separations.