High-temperature-resistant sulfonated polybenzothiazole imide proton exchange film and preparation method thereof

Abstract

The invention relates to a high-temperature-resistant sulfonated polybenzothiazole imide proton exchange film and a preparation method thereof, the preparation method comprises the following steps: firstly, mixing a dianhydride monomer with a diamine monomer containing a benzothiazole structure to generate polyamide acid; then adding at least one of water-carrying agents methylbenzene, xylene or chlorobenzene to obtain a sulfonated polybenzothiazole imide solution; and evaporating out the water-carrying agent, pouring a reaction liquid into methanol, separating out a solid product, fully washing the solid product with methanol or diethyl ether, filtering and drying so as to obtain sulfonated polybenzothiazole imide solid product powder; dissolving the obtained sulfonated polybenzothiazoleimide solid product powder in an aprotic polar solvent to form a polymer solution with the solid mass content of 5-20%, and uniformly coating flat glass with the polymer solution; then drying in an inert atmosphere drying oven or a vacuum drying oven according to a certain heat treatment program; and stripping a film after drying to obtain the sulfonated polybenzothiazole imide proton exchange film with the thickness of 10-50 microns.

Description

technical field [0001] The invention relates to the synthesis of sulfonated polybenzothiazole imide and the preparation of its proton exchange membrane, in particular to a high temperature resistant sulfonated polybenzothiazole imide proton exchange membrane and its Preparation. Background technique [0002] With the development of polyelectrolyte membrane fuel cells (PEMFC), the fuel cell industry has increasingly high performance requirements for proton exchange membranes (PEM). Traditional perfluorosulfonic acid proton exchange membranes represented by Nafion, Flemion, Aciplex and Dow have excellent electrical conductivity and chemical corrosion resistance, making them widely used and industrialized in fuel cells. However, these PEM membranes still have some performance disadvantages; for example, taking Nafion membrane as an example, there are two main problems in this membrane: one is the high methanol permeability, which results in a decrease in the energy efficiency ...

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Problems solved by technology

However, these PEM membranes still have some performance disadvantages; for example, taking Nafion membrane as an example, there are two main problems in this membrane: one is the high methanol permeability, which results in a decrease in the energy efficiency of the battery and at the same time increases the burden on the cooling system; the other The problem is that the conductivity of this membrane is heavily dependent on the amount of water in the membrane, and when the relative humidity is 100%, the conductivity of this membrane is 6.2*10 - 2 Scm -1 , the conductivity of this film dropped by 2 orders of magnitude when the relative humidity was reduced to 9%

Since the proton conductivity of the above-mentioned sPI is heavily dependent on the water content in the PEM, it is difficult to ensure the uniformity of the film thickness of the PEM obtained by doping with inorganic substances, and there is a problem of ring-opening hydrolysis of the imide ring under high-temperature acidic conditions, thus reducing The service life of the above sPI is shortened, which in turn limits the use of sPI in high temperature and specific humidity environments

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