Network cross-linking of polyimide membranes for pervaporation dehydration

Amine cross-linking is one of the popular modifications of polyimide membranes in order to improve their operation stability and separation performance. In this work, a novel kind of cross-linker tricarbohydrazide - 1,3,5-benzenetricarboxylic acid trihydrazide (BTCH), is synthesized and incorporated into polyimide membranes for isopropanol dehydration via pervaporation. The chemical structure of BTCH is examined by NMR and FTIR to confirm the successful synthesis. The effects of BTCH content and membrane-forming temperature on the membrane physicochemical properties and separation performance are studied and characterized by various techniques. And the possible reaction mechanism during the chemical cross-linking is proposed and analyzed. This work is believed to shed useful insights on the chemical modification of polyimide membranes for pervaporation and other membrane-based separation applications. (C) 2017 Elsevier B.V. All rights reserved.