Cross-linked Alkaline Exchange Membrane For Fuel Cell

At present, PEMFC mainly adopted the strong acidic electrolyte membrane which is represented by Nafion. However, the choice of catalysts which is used for oxidation of methyl alcohol and has the character of high activity and high stability is limited. And problem of the permeation of methyl alcohol in the system of membrane remain unsolved which limit the development of acidic membrane. Nevertheless, a new system of fuel cell of Alkaline Anion Exchange Membrane Fuel Cell is emerging. As a key part of AAEMFC, the quality of alkaline anion exchange membrane (AAEM) determines the quality of the fuel cell. The research of AAEM bagin relatively late and existing the problem of low ion conductivity and low stability which can't satisfy the requirement of AAEMFC. The main purpose of this article is to prepare the cross-linked AAEM based on PPEK with the quality of high conductivity and high stability and carry out a systematic research on varies property of the membrane.First, using chloromethyl methyl ether(CME) as chloromethylation reagent and adopting common method of conducting chloromethylation reaction on PPEK and getting the product of chloromethylate polyether ketone(CMPPEK). Through technique optimization, we got the chloromethylate polyether ketone with different degree of chloromethylation (DCM) and the membranes were characterized by the methods of 1H-NMR and chemical titration. The range of the degree of chloromethylation is 1.25-3.60 mmol/g by controlling reaction factors which provide a relatively high degree of chloromethylation and a wide range for choosing the corresponding materials for preparating.Second, we carried out cross-linked and quaternary ammonium reaction using N,N-tetramethyl ethylenediamine as crosslinking and quaternary reagent. Through the process of crosslinking, membrane preparation, quaternization, alkalization et al., we successfully preparation the membrane of crosslinked heterocycle polyether ketone anion exchange membrane (AAEM). We investigated the effect on the membrane property of swelling ratio, moisture content and conductivity et al. that is caused by the crafts of quaternary ammonium. The conductivity of the alkaline membrane is at the magnitude of 10-2, and the degradation time under the temperature of 60℃and in the circumstance of strong alkaline solution that has a concentration of 6 mol/L is seven days. The thermostability and solvent resistance presented good as well. Therefore, it has a potential to be used in alkaline anion exchange membrane in fuel cell.Last, we carried out the experiment of quaternary ammonium reaction, membrane preparation, alkalization by using composite agent of N-methylimidazole and N, N-tetramethyl ethylenediamine, successfully prepared the membrane of crosslinked heterocycle polyether ketone anion exchange membrane(AAEM). We characterized the property of ion exchange capacity (IEC), swelling ratio, moisture content and conductivity et al. The results showed that the alkaline membrane with a degree of chloromethylation of 3.28 mmol/g, had swelling ratio of 7.6% and ion conductivity of 0.032 S/cm, which present a good overall performance and has a potential to be used in alkaline anion exchange membrane in fuel cell.