摘要 |
[PROBLEMS] This invention provides a binder for fuel cell, which has high adhesion, low methanol solubility, high methanol permeability and high proton conductivity, a composition for electrode formation, an electrode for a fuel cell, and a fuel cell using them. The binder is particularly suitable as a binder for a direct methanol-type fuel cell which requires high proton conductivity. [MEANS FOR SOLVING PROBLEMS] The binder for a fuel cell comprises a block copolymer that comprises blocks comprising repeating structural units of a protonic acid group-containing divalent aromatic group and blocks comprising repeating structural units of a protonic acid group-free divalent aromatic group and has a glass transition temperature (Tg) of 180‹C or below. In particular, preferably, the block copolymer has an ion exchange group equivalent of 200 to 1000 g/mol and a weight retention of not less than 90% as measured by immersion in a 64 wt% aqueous methanol solution at 25‹C for 24 hr. ® KIPO & WIPO 2007
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