Title of Paper:Friedel-Crafts alkylation route for preparation of pendent side chain imidazolium-functionalized polysulfone anion exchange membranes for fuel cells

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Date of Publication:2019-03-01

Journal:JOURNAL OF MEMBRANE SCIENCE

Included Journals:SCIE、Scopus

Volume:573

Page Number:157-166

ISSN No.:0376-7388

Key Words:Friedel-Crafts alkylation; Anion exchange membranes; Pendent side chain; Micro-phase separation; Low swelling ratio

Abstract:Friedel-Crafts alkylation route is proposed to synthesis polysulfone based anion exchange membrane (AEM) containing pendent imidazolium-functionalized side chain with the purpose of avoiding conventional carcinogenic chloromethylation. It has no special functional group requirements on the polymer materials, which has advantage over those reported chloromethylation free routes. A novel flexible alkylation reagent containing -(CH2)(4)- spacer, (1-chlorobutyl-2,3-dimethylimidazole chloride) is synthesized and promotes hydrophilic/hydrophobic micro-phase separation structure in the membranes proved by small angle X-ray scattering (SAXS) and transmission electron microscopy image (TEM). The imidazolium-functionalized polysulfone AEMs prepared by the Friedel-Crafts alkylation route in this study exhibit first level properties compared to other AEMs prepared without chloromethylation. The ion conductivity-normalized swelling ratio (0.08% cm mS(-1) at 80 degrees C) is the lowest, while exhibits higher or equivalent IEC normalized ion conductivity (56.8 S g cm(-1) mol(-1) at 80 degrees C). The membranes prepared in this work also display good thermal, mechanical and alkaline stabilities.