Anhydrous proton conducting membranes based on crosslinked graft copolymer electrolytes

作者：Kim Yong Woo; Park Jung Tae; Koh Joo Hwan; Roh Dong Kyu; Kim Jong Hak^*

来源：Journal of Membrane Science, 2008, 325(1): 319-325.

DOI：10.1016/j.memsci.2008.07.043

• Atom transfer radical polymerization (ATRP)
• Comb copolymer
• Crosslinked
• Proton conductivity
• Anhydrous polymer electrolyte membrane

A comb-like copolymer consisting of a poly(vinylidene fluoride-co-chlorotrifluoroethylene) backbone and poly(hydroxy ethyl acrylate) side chains, i.e. P(VDF-co-CTFE)-g-PHEA, was synthesized through atom transfer radical polymerization (ATRP) using CTFE units as a macroinitiator. Successful synthesis and a microphase-separated structure of the copolymer were confirmed by proton nuclear magnetic resonance ((1)H NMR), FT-IR spectroscopy, and transmission electron microscopy (TEM). This comb-like polymer was crosslinked with 4,5-imidazole dicarboxylic acid (IDA) via the esterification of the -OH groups of PHEA and the -COOH groups of IDA. Upon doping with phosphoric acid (H(3)PO(4)) to form imidazole-H(3)PO(4) complexes, the proton conductivity of the membranes continuously increased with increasing H(3)PO(4) content. A maximum proton conductivity of 0.015 S/cm was achieved at 120 degrees C under anhydrous conditions. In addition, these P(VDF-co-CTFE)-g-PHEA/IDA/H(3)PO(4) membranes exhibited good mechanical properties (765 MPa of Young's modulus), and high thermal stability up to 250 degrees C, as determined by a universal testing machine (UTM) and thermal gravimetric analysis (TGA), respectively.

• 出版日期2008-11-15