CPC H01M 8/1072 (2013.01) [C08G 73/18 (2013.01); H01M 8/1067 (2013.01); H01M 8/1081 (2013.01); H01M 8/1086 (2013.01)] | 4 Claims |
1. A preparation method of comb-shaped polybenzimidazole anion exchange membrane, comprising the steps as follows:
(1) synthesis of deprotonated comb-shaped side chain grafted polybenzimidazole material: dissolving polybenzimidazole in solvent A to form a solution with a mass fraction of 1-5 wt. %, and then adding acid binding agent and side chain R2-R3-R4 without quaternary ammonium cations; molar ratio of the side chain R2-R3-R4 without quaternary ammonium cations and acid binding agent to N—H proton is both greater than 1:1; reacting at −18° C. to 100° C. for 48-168 h until a bright yellow liquid is formed; the bright yellow liquid produced is precipitated in precipitator B to obtain a solid, which is filtered and dried in vacuum at room temperature for 12-24 h to obtain a deprotonated comb-shaped side chain grafted polybenzimidazole material;
the side chain R2-R3-R4 without quaternary ammonium cation, wherein R2 is halogen, aldehyde group or epoxy group;
(2) preparation of comb-shaped structure polybenzimidazole anion exchange membrane: dissolving the deprotonated comb-shaped side chain grafted polybenzimidazole material obtained in step (1) in DMSO solvent to form a solution with a mass fraction of 1-5 wt. %, followed by adding quaternization reagent and reacting at 40° C. to 100° C. for 24-48_h, and obtaining a reaction solution; pouring the reaction solution into precipitator C, a solid product is precipitated, filtered and dried at room temperature for 12-24 h, comb-shaped structure polybenzimidazole material is obtained, dissolving the comb-shaped structure polybenzimidazole material in DMSO solvent to form a casting solution with a mass fraction of 1-5 wt. %, and then casting the casting solution into a membrane, which is dried under a condition of 60° C. for 48-96 h; immersing the membrane in 1 MKOH solution for 24-72 h, and then washing to neutral in deionized water to obtain the comb-shaped structure polybenzimidazole anion exchange membrane;
the solvent A is a mixture of one or more of DMF, DMAc, NMP or DMSO; a precipitant B is one or more of water, ethyl acetate or acetone; and the precipitant C is ethyl acetate or acetone or a mixture of both;
a reaction formula is as follows:
molecular structure of the comb-shaped structure polybenzimidazole anion exchange membrane is as follows:
wherein 0<x≤1;
structure of —R1- is as follow, and each —R1- is a same structure or a different structure:
R3 is a carbon chain containing ether oxygen bond, with a total length of 1-14 atoms; each R3 is a same structure or a different structure;
R4 is a hydrogen atom or halogen; each R4 is a same structure or a different structure;
R5 is a quaternary ammonium cation, and each R5 is a same structure or a different structure.
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