Preparation And Properties Of Side Chain Type Poly(Arylene Ether Ketone) Proton Exchange Membranes Based On Ullmann C-N Coupling Reaction

Because of fossil fuel shortage, seeking for alternative clean energy has become the urgent matter to overcome energy crisis. Proton exchange membrane fuel cells, with its high energy conversion rate, fast response at low temperature, emissions harmless and many other advantages, have become the most promising alternative to fossil fuels. Proton exchange membranes(PEMs) are the core components of proton exchange membrane fuel cells. Nafion, as the representative of the perfluorosulfonic acid proton exchange membrane, is now the most widely used commercial PEMs because of its stable chemical structure, good mechanical properties and high proton conductivity. However, Nafion is still facing a series of issues. At temperatures above 80 oC, the mechanical properties of Nafion is weaken and the conductivity reduces resulting in poor performance in practical application. Meanwhile, the manufacturing procedure of Nafion is costly, which also restricts its application. So PEMs with low cost and high performance become the focus of research work for many scientific researchers.Sulfonated poly(aryl ether ketone)s polymer with excellent chemical stability, thermal stability and mechanical properties, have great advantages in the PEMs preparation. In order to obtain higher proton conductivity, it is necessary to increase the sulfonated polymer ion exchange capacity(IEC), but this will also increase the rate of swelling of the materials. In order to achieve a balance, Ullmann grafting reaction was employed in this paper to prepare a series PAEKs containing sulfonated pendants, and the properties of these materials were detailed.In this paper, Ullman C-N coupling reaction was introduced to prepare a series PAEKs proton exchange membrane. In order to achieve this purpose, 4-iodophenyl hydroquinone was prepared as monomer for the Ullmann coupling reaction. 3,6-diphenyl-9H-carbazole and 3,6-ditrityl-9H-carbazole were also prepared as two grafting compounds. And through Ullmann CN coupling reaction, sulfonation with chlorosulfonic acid and casting method, a series of films were obtained. Through the investigations of water uptake, swelling ratio, thermal stability, proton conductivity, mechanical properties, oxidation stability and morphology, the films showed its potential application in PEMs.