Method for preparing anion-exchange membrane with multi-crosslinked structure

Abstract

The invention discloses a method for preparing an anion-exchange membrane with a multi-crosslinked structure. The method comprises the following steps: (1) dissolving bromoethylated polyphenyl ether in N-methyl pyrrolidone to form a membrane casting solution, coating the membrane casting solution on a flat panel with a knife or coating the membrane casting solution on a supporting cloth, soaking in a coagulating bath, and drying to obtain a porous base membrane; (2) mixing 1-vinyl imidazole, bromopropane and isopropanol to enable the system to react; adding divinyl benzene, radical initiator and organic solvent after the reaction, and uniformly stirring to obtain a monomer solution; (3) soaking the porous base membrane with the monomer solution, putting the porous base membrane between twoPET films to form a complex; and heating the complex at the temperature of 60-100 DEG C, and releasing the two PET films to obtain an anion-exchange membrane semi-finished product; and (4) performingheat post-treatment on the anion-exchange membrane semi-finished product at the temperature of 130-150 DEG C to obtain the anion-exchange membrane. The anion-exchange membrane prepared by the methodhas low resistance, high transport number, good swelling resistance and good solvent resistance.

Description

technical field [0001] The invention relates to a preparation method of an anion exchange membrane, in particular to a preparation method of an anion exchange membrane with multiple cross-linked structures, and the membrane is suitable for electrodialysis process. Background technique [0002] Since Juda and McRac of American Ionics Company in 1950, and Winger of Rohm Company in 1953 invented ion-exchange membranes with excellent performance, ion-exchange membranes and related technologies have developed rapidly. In the 1960s, Asahi Kasei Corporation of Japan realized the industrialization of salt production from seawater with monovalent ion exchange membranes; in the 1970s, Du Pont Corporation developed perfluorosulfonic acid and carboxylic acid composite membranes (cation exchange membranes) with very stable chemical properties. Membranes, Nafion® series), realize the large-scale application of ion exchange membranes in the chlor-alkali electrolysis industry and energy sto...

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Problems solved by technology

In Chinese patent CN105903357A, bromomethylated polyphenylene ether is dissolved in a mixed solution composed of chloromethylstyrene and styrene, then vinylimidazole is added, stirred to complete the reaction, and then 1-methylimidazole is added, and stirred evenly The quaternized membrane solution is obtained, and then the membrane solution is coated on the reinforced fabric and dried to obtain an anion exchange membrane; the vinyl group of vinylimidazole participates in the copolymerization reaction of other monomers, and at the same time its imidazole unit is combined with bromomethylated polymer The bromomethyl reaction of phenylene ether makes the polyphenylene ether molecular chain and the polymer molecular chain formed by monomer polymerization form a crosslink; however, in order to make the prepared anion membrane have enough ion exchange groups, the preparation process needs Adding a sufficient amount of aminating agent (1-vinylimidazole and 1-methylimidazole), the aminating agent not only reacts with chloromethylstyrene, but also reacts with bromomethylated polyphenylene ether, resulting in The polyphenylene ether is fully quaternized and affects the mechanical strength and dimensional stability of the membrane

However, this process of amination after film formation increases the film-making process, and the volatility and strong fishy smell of trimethylamine during the amination process make the control of the film-making process complicated.

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