High-temperature crosslinked chitosan/nitrogenous phosphonic acid polysiloxane proton exchange membrane and preparation method thereof

Abstract

The invention relates to a high-temperature crosslinked chitosan / nitrogenous phosphonic acid polysiloxane proton exchange membrane and a preparation method thereof. The membrane is obtained by the following steps: (1) preparing a chitosan liquid; (2) preparing an organic nitrogenous phosphonic acid liquid; (3) slowly dropwise adding the organic nitrogenous phosphonic acid liquid to the chitosan liquid, fully stirring evenly to obtain a mixed liquid, and slowly dropwise adding amino siloxane to the mixed liquid, so as to obtain a sol liquid; (4) slowly adding an aldehyde crosslinking agent to the sol liquid, and stirring evenly, so as to obtain a gel liquid; and (5) pouring the gel liquid into a polytetrafluoroethylene mold, ageing at a room temperature for 2-3 days, drying at 80 DEG C, then sequentially carrying out heat treatment at 100 DEG C, 120 DEG C and 150 DEG C for 2 hours respectively, cooling and stripping off from the polytetrafluoroethylene mold, so as to obtain the high-temperature crosslinked chitosan / nitrogenous phosphonic acid polysiloxane proton exchange membrane. The preparation method is simple, and mild in reaction condition; the prepared proton exchange membrane has the advantages of relatively high proton conductivity and good heat stability under high-temperature and anhydrous conditions.

Description

technical field [0001] The invention belongs to the technical field of fuel cells, and relates to a cross-linked chitosan / nitrogen-containing phosphonic acid group polysiloxane high-temperature proton exchange membrane and a preparation method thereof. Background technique [0002] A proton exchange membrane fuel cell (PEMFC) is a type of fuel cell system that uses a proton exchange membrane as an electrolyte. This type of fuel cell is also often referred to as a solid polymer fuel cell. The proton exchange membrane is the core component of the fuel cell, which directly affects the performance and life of the battery. Proton exchange membranes for PEMFC need to have high H + It also needs to have good proton conductivity and certain mechanical strength under high temperature and low humidity working conditions. [0003] At present, the commonly used proton exchange membrane materials include polymers such as perfluorosulfonic acid polymers, polyaryletherketones, polyethere...

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Problems solved by technology

However, as the temperature increases, the ion cross-linking effect between phosphotungstic acid and chitosan weakens, and a part of phosphotungstic acid will leak out, resulting in a decrease in electrical conductivity (Cui Z, Liu C, Lu T, et al. .Polyelectrolyte complexes of chitosan and phosphotungstic acid as proton-conducting membranes for direct methanol fuel cells[J].Journal of Power Sources,2007,167(1):94-99.)