GOALI: Gas Transport and Barrier Properties Aromatic Polyamides

摘要CTS-9803225本尼·弗里曼/北卡罗来纳州美国专利无定形聚酰胺用于气体分离应用；液晶(LC)芳香族聚酰胺是目前最不透气的阻隔聚合物之一。然而，通常情况下，全芳香族聚酰胺，特别是液晶聚酰胺，通常很难溶解，熔点接近或高于其分解温度；因此，这些材料的熔融和溶液处理可能相当困难。此外，新型高性能芳香族聚酰胺的合成会因其缺乏溶解性而受到阻碍。拟议的实验研究计划是前两年计划的继续，目的是探索一类新的高度溶解的全芳香族聚酰胺的合成和气体吸附、运输和渗透性能，具有刚性棒、可能是介晶、骨架或半棒状骨架和结构元素，这些结构元素可能是进一步反应的前体，如交联剂或悬挂的刚性或柔性基团的附着。这些基础性研究旨在开发一种更广泛、更微妙的结构修饰体系，有助于合理地剪裁超薄膜和超屏障。所考虑的论文的中心概念是，所提出的一级化学结构变化可能显著影响聚合物的超结构(即聚合物链堆积)、聚合物与载体的相互作用，进而强烈地影响气体的吸附、传输和渗透性能。提出了一种实验方案，涉及控制合成具有取代基的高度可溶的全芳香族聚酰胺，这些取代基可用于交联聚合物或连接刚性或柔性侧链。这些聚合物的化学结构、物理性能和气体传输特性将被表征，以明确地确定侧链和主链分子结构、侧链刚性以及交联势对整体吸附、传输和渗透行为的影响。***

ABSTRACT CTS-9803225 Benny Freeman/N.C. State U. Proprietary amorphous polyamides used commercially in gas separation applications; liquid crystalline (LC) aromatic polyamides area among the most impermeable barrier polymers available. However, wholly aromatic polyamides in general and LC ones in particular are typically difficult to dissolve and have melting points near or above their decomposition temperatures; melt and solution processing of these materials can be, therefore, quite difficult. Moreover, the synthesis of new higher performance aromatic polyamides can be impeded by their lack of solubility. The proposed experimental research program is a continuation of an earlier two year program to explore the synthesis and gas sorption, transport, and permeation properties of a new class of highly soluble wholly aromatic polyamides, having either rigid rod, possibly mesogenic, backbones or semi-rodlike backbones and structural elements which could be precursors for further reactions such as crosslinking or the attachment of pendent rigid or flexible groups. These fundamental studies are directed toward developing an expanded and more subtle repertoire of structural modification useful for the rational tailoring of super-membranes and super-barriers. Central to the thesis under consideration is the notion that the proposed primary chemical structure variations could markedly influence polymer suprastructure (i.e. polymer chain packing), polymer-pentrant interactions, and, in turn, strongly effect gas sorption, transport, and permeation properties. An Experimental program is proposed involving controlled synthesis of highly soluble wholly aromatic polyamides having substituents which could be used to crosslink the polymers or attach rigid or flexible side chains. The chemical structure, physical properties, and gas transport properties of these polymers would be characterized to determine explicitly the influence of side and main chain molecular architecture and side chain stiffne ss, plus the potential for crosslinking, on the overall sorption, transport, and permeation behavior. ***