Processable Precursors to High Performance Liquid Crystalline Polymers.

摘要

Processable precursor polymers to aramids, poly(imino-1,4-phenyleneiminocarbonyl-1,4 phenylenecarbonyl) and poly(imino-1,3-phenyleneiminocarbonyl-1,4-phenylenecarbonyl), were prepared and studied. The precursor polymers were made from the reaction of 2,5-dichlorobicyclo2.2.2octane-1,4-dicarbonyl chloride or 2,5diacetoxybicyclo2.2.2octane-1,4-dicarboxylic acid. The polymeric precursors were subsequently converted in approximately 98% - 100% yields, via dehdrohalogenation and retro Diels-Alder reactions to the corresponding aramids by refluxing in 1M solution of potassium hydroxide or sodium hydroxide, or by bulk pyrolysis using aromatization catalysts, such as, ZnCl2 and dichlorobenzene sulfonic acid. Only the p-phenylene precursor polymer exhibited liquid crystal characteristics in solution. Thermal properties were examined and tensile properties will be determined In a future study.