Study On Preparation And Of HTPEMS Based On Poly (Phenyleneoxide)

Fuel Cell is an electrochemical device which can convert chemical energy (hydrogen, hydrocarbons, etc.) into electrical energy directly. Among them, due to the improvement of the fuel cell operating temperatures the high-temperature proton exchange membrane fuel cells show:the enhanced CO tolerance of anodic catalysts, potentially improved electrode kinetics and proton conductivity, simplified thermal and water management systems, and the ability to use non-platinum catalysts and reformate hydrogen. PEMs used for high temperature proton exchange membrane fuel cells (HTPEMFCs) have been a popular research area in the field of FCs. Although polybenzimidazole (PBI) represented by the high temperature proton exchange membrane is considered to be the most promising of the film material, but the disadvantages such as its poor solubility, the complicated preparation process, difficult processing limit its commercial applications. Therefore, high efficiency, low cost, making the process simple and easy process, especially the new high-temperature aqueous environment of high temperature proton conductivity high proton exchange membrane development has become an urgent problem.Poly (2,6-dimethyl-1,4-phenylene oxide) (PPO) possess many desirable properties that can meet most of the requirements for applications in HTPEMFCs because it is a hydrophobic polymer with a high glass transition temperature (Tg=210?), high mechanical strength, and excellent hydrolytic stability. At the same time, compared with the structures of other aromatic polymers, the simple structure of PPO allows many modifications at both the aryl and the benzyl position. Specific contents are as follows:Part One:Imidazolium-functionalized poly (2,6-dimethyl-1,4-phenylene oxide) (PPO) doped with phosphoric acid for high temperature proton exchange membrane fuel cells.We designed and synthesized a series of Imidazolium-functionalized Poly (2,6-dimethyl-1,4-phenylene oxide) s (Im-PPOs) containing pendent imidazole groups which were used to supply functional sites for acid-base interaction with the doping phosphoric acid. We prepared brominated poly(2, 6-dimethyl-1,4-phenylene oxide) (BPPO) by bromomethylated reaction, and then the poly (2,6-dimethyl-1,4-phenylene oxide)s (Im-PPOs) were imidazolium functionalized by the reaction of BPPO with each of 1-methylimidazole (MeIm),1-ethylimidazole (EtIm),1-propylimidazole (PrIm),1-butylimidazole (BuIm), and 1-vinylimidazole (Vinlm). The PA content, area swelling, and tensile strength of the different membranes doped with PA were measured. With the increase of length of side chains on the imidazole groups, the membranes showed different properties. A proton conductivity of 3.7×10-2 S/cm was obtained at 160? by the MeIm-PPO imidazolium acid-base composite membrane.Part Two:Study on preparation and characterization of HTPEMS based on quaternized poly (2,6-dimethyl-1,4-phenylene oxide) s (QPPO)Brominated poly (2,6-dimethyl-1,4-phenylene oxide) was obtained (BPPO) by the reaction of bromomethyl and BPPO react with trimethylamine, triethylamine, tripropylamine to get different quaternized poly (2, 6-dimethyl-1,4-phenylene oxide) s. After that, the high-temperature proton exchange membrane obtain by the solution casting method, and the membrane performance characterization was tested. The trimethylamine side chain (TriMe-PPO) showed best performance composite membrane proton conductivity reached 30mS/cm at 160?.Part Three:Study on preparation and characterization of HTPEMS based on Ionic Liquid Poly (2,6-dimethyl-1,4-phenylene oxide) sFirst, we prepared different degrees of sulfonated Poly (2, 6-dimethyl-1,4-phenylene oxide) (SPPO), and to study the relation between the amount of chlorine added acid and sulfonated ion exchange capacity. Preparation of ionic liquid and 1-methyl-3-methylimidazolium salt (1-methyl-3-methylimidazolium), and sulfonated Poly (2, 6-dimethyl-1,4-phenylene oxide) e (SPPO) composite film obtained by self-assembly. Membrane characterization and performance was tested. Proton conductivity reached the highest rate of 26.4mS/cm.