Preparation and Characterization of Proton Exchange Membrane Composite of PEG Modified Sulfonated Polyfluoroether Sulfone and Different OMMT Applied to DMFC

• Main Authors: CHEN,PO-WEI, 陳柏瑋
• Other Authors: Liao,Wei-Tung
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/f82upv

碩士 === 南臺科技大學 === 化學工程與材枓工程系 === 105 === In this study, using the synthesized PEG (Polyethylenglycol) modifier composite membrane to fabricate MEA (Membrane Electrode Assembly) and evaluating the performance of the single cell. The synthesis experiment will be conducted by condensation polymerization of hydroquinone 2-potassium sulfonate, hexafluoro-bisphenol A, 4-fluorophenyl sulfone and PEG. We have already synthesized copolymer without PEG and find out that it has a poor water uptake and proton conductivity property. We expect that to introduce a hydrophilic polyethylenglycol (PEG) will increase the water uptake ratio of the resultant copolymer. After the purification of the above synthesized polymer products, and use the FT-IR, 1H NMR to confirm the polymer. The ion exchange capacity of the polymer was 1.03mmol/g. In addition , the high methanol permeability can be reduced by the adding of organically treated nanomontmorillonite (OMMT) into the polymer matrix. The copolymer will well-mixed with OMMT to make a composite and it will be used to produce a low methane penetration proton exchange membrane. There were three commercial modified montmorillonites, TSA (trimethyl steary ammonium), DDA (dimethyl dialkyl amine) and MDHTA (methyl dihydroxyethyl hydrogenated tallow ammonium) were chose and added into previous copolymer respectively. After 4% modified montmorillonite added, the highest water absorption of the three composites is 20%. Besides the contact angle is slightly decreased after the addition of OMMT. By the electron microscope it can be clearly observed stereoscopic sheet structure, and the other test show that a proton exchange membrane with a methanol crossover of 2.03×10-9cm2/s and a selectivity ratio of 1.672×107 S×s/cm3 were obtained by adding 4wt% of MDHTA-MMT. Three OMMT modified MEAs being conducted a single cell performance tests, the addition of TSA-MMT composite membrane has an open circuit voltage of 0.637V, and the maximum power density is 15.89 mW. After 3 hours endurance test, it can still maintain an open circuit voltage of 0.623V, and a highest power density of 12.15mW.