Alkali-resistant anion-exchange membrane loaded with substituted imidazole units and preparation method thereof

Abstract

The invention relates to a substituted imidazole unit loaded alkali-resistant anion exchange membrane and a preparation method of the alkali-resistant anion exchange membrane, and belongs to the technical field of anion exchange membranes for fuel cells. A structural formula is as shown in the specification; R1 is aryl or one of C1-C8 alkyl; R2 is aryl or C1-C8 alkyl; R3 is C1-C8 alkyl; R4 is anyone of C1-C8 alkyl; R5 is any one of C1-C18 alkyl; and n is a degree of polymerization of polyphosphazene. The method comprises the steps of adopting imidazole containing different substituent groupsand polydichlorophosphazene for reaction to form a novel substituted imidazole unit loaded polyphosphazene material, and performing membrane forming and ion exchange to form the alkaline anion exchange membrane. The substituted imidazole unit loaded alkali-resistant anion exchange membrane does not involve in the problems of Hofmann degradation, Ei elimination, nucleophilic substitution and the like of the conventional quaternary ammonium anion exchange membrane; the degradation problem in a high temperature strongly alkaline environment is avoided; and the anion exchange membrane has the characteristics of high ion conductivity and excellent alkali resistance.

Description

technical field [0001] The invention belongs to the technical field of anion exchange membranes for fuel cells. In particular, it relates to a class of alkali-resistant anion exchange membrane loaded with substituted imidazole units and a preparation method thereof. Background technique [0002] In this era of faster and faster replacement, long-term dependence on traditional fossil energy is far from meeting our needs. In the process of exploration, many new energy conversion methods have emerged, among which wind energy, solar energy, fuel cells, etc. are representative. Anion exchange membrane fuel cell is a kind of fuel cell, because it can use non-Pt catalyst, simple hydrothermal management and low fuel permeation, etc., it has been paid more and more attention by researchers at home and abroad. At present, there are two main factors that limit the development of anion exchange membranes: one is low ion conductivity, and the other is poor alkali resistance. Improving...

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Problems solved by technology

[0004] Chinese patent (Application No. 201210212672.X) discloses a highly alkali-resistant imidazole ionic liquid and its application: add monomers, imidazole ionic liquids, and cross-linking agents into a reaction vessel, and in-situ polymerize under ultrasonic vibrations. Polymer anion exchange membrane, but the report did not involve the C of the imidazole unit 4 、C 5 There are different substituent groups attached to the positions, and no imidazole units are loaded onto the polyphosphazene backbone to prepare anion exchange membranes.

[0006] Frederick L. Beyer tested the C of imidazole in the literature (ACS Macro Lett.2014,3,160-165) 2 The impact of methyl substituents and tert-butyl substituents on the alkali resistance of imidazoles, this report did not carry out the research on the synthesis of anion exchange membranes by loading imidazole units on the polyphosphazene backbone

[0007] Geoffrey W. Coates synthesized and studied the influence of substituent groups around imidazole on the alkali resistance of imidazole in the literature (J.Am.Chem.Soc.2015,137,8730-8737), which was not involved in this report Loading of imidazole units onto the polymer backbone for the study of anion exchange membranes

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