INTEGRATED PROCESSES FOR THE PREPARATION OF POLYBENZIMIDAZOLE PRECURSORS

摘要

An integrated process is provided for efficiently preparing 2,4,5-triaminophenol, starting with nitration of 2,6-dihalobenzene; high purity salts thereof; and complexes of 2,4,5-triaminophenol aromatic diacids, which are precursors for making polybenzimidazole polymer for high performance fibers. The process design eliminates several costly intermediate drying and recrystallization steps. The handling of solid materials with possible skin sensitizing properties and toxicity is avoided, thereby eliminating human and environmental exposure.