A novel cross-linked anion exchange membrane with conjugated and non-conjugated pyridine groups

A novel cross-linked pyridine anion exchange membrane was synthesized via thermal cross-linking methods. 2,5-bis(2,3,4,5,6-pentafluorophenyl)-1,3,4-oxadiazole (FPOx) and diallyl bisphenol A (DABPA) were reacted to obtain the main polymer chain (MP). MP was substituted with 4-bromopyridine and 4-hydroxypyridine to generate two pyridine polymers conjugated pyridine polymer (CPP) and non-conjugated pyridine polymer (NPP). The different conjugation statues of CPP and NPP led to distinct mechanical and electrochemical properties. The diallyl groups in MP acted as the cross-linking structures which strengthened the mechanical properties of CPP and NPP and provided more flexible side chains. The ultimate membrane CPP-membrane and NPP-membrane were prepared by solution casting methods. Compared with NPP-membrane, the ionic conductivity of CPP can achieve to 20.1 mS/cm at 20 degrees C with excellent mechanical and thermal characteristics. Quantum theory computation and AFM morphology were carried out to figure out the reason of the difference in ionic conductivities and physical properties. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.