Styrene-based copolymer for electrode binder of solid alkaline fuel cell and membrane electrode assembly comprising the same

A method for preparing an electrode binder of a solid alkaline fuel cell, comprising the steps of:

• (1) polymerizing a styrene-based polymer;
• (2) substituting a part of phenyl groups of the styrene-based polymer with acyl groups to obtain an acyl group-substituted styrene-based polymer;
• (3) reducing ketone groups of the acyl group-substituted styrene-based polymer to obtain a ketone group-reduced styrene-based polymer;
• (4) substituting the ketone group-reduced styrene-based polymer with quaternary ammonium to obtain a quaternary ammonium-substituted styrene-based polymer;
• (5) reacting the quaternary ammonium-substituted styrene-based polymer with an aqueous basic solution so that the halogen ions ionically bound to quaternary ammonium may be substituted with hydroxide ions (OH−), thereby providing a styrene-based copolymer represented by the following Chemical Formula 1,
• wherein x is an integer of 2-10, and
• each of m and n represents the number of repeating units,
• wherein the styrene-based copolymer has a molecular weight (Mn) of 5,000-200,000 q/mol;
• and
• (6) dispersing the styrene-based copolymer in a mixed solvent including 25-400 parts by weight of water based on 100 parts by weight of alcohol.