4-Vinylimidazole-co-acrylic acid copolymer: An approach to develop nonaqueous proton transferring system in polymer electrolyte membrane

FUEL 17

Manita Jithunsa, manitatar@yahoo.com1, Kohji Tashiro, ktashiro_001@yahoo.co.jp2, and Suwabun Chirachanchai, csuwabun@chula.ac.th1. (1) Department of Polymer Science, The Petroleum and Petrochemical College, Chulalongkorn University, Chula Soi 12, Phyathai road, Pathumwan, Bangkok, 10330, Thailand, (2) Department of Future Industry-Oriented Basic Science and Materials, Toyota Technological Institute, 2-12-1, Hisakta, Tempaku, Nagoya, Aichi, 468-8511, Japan
Polymer electrolyte membrane fuel cell (PEMFC) has been received much attention for the past decades as it is a simple and clean alternative energy resource developed from the proton exchange system in the polymeric electrolyte membrane. At present, perfluorosulfonic acid polymer, Nafion®, is known as an effective membrane providing the proton conductivity as high as 10-2 S/cm in its fully hydrated state at 60-80°C. Currently, heterocyclic aromatic compounds, especially imidazole, have been proposed for the protonic charge carrier functioning even at high temperature (above 120°C) without the needs of hydration. Here, we challenge a copolymer system consisting of proton donor moiety of acrylic acid and proton acceptor group of 4-vinylimidazole. From impedance preliminary result, Nafion shows the proton conductivity in the range of 20-50 mS/cm under fully hydrate condition. For poly(AA-co-4-VIm) with monomer feed ratio of 19:1, the proton conductivity under anhydrous condition is stable at 15 mS/cm up to 125°C. In the presentation, we will cover the synthesis, characterization, membrane preparation, thermal stability and the proton exchange properties.