Study On Poly(pyridobisimidazole)polymer Electrolyte Membranes

Polymer electrolyte membrane fuel cell?PEMFCs?is a new energy source due to its high efficiency,clean and energy renewable.As a key component of the PEMFCs,the polymer electrolyte membrane?PEMs?can separate the fuel at the two poles,transfer the ions,and insulate the electron.Currently,the commercial PEMs are mainly Nafion membrane.However,these membranes not only have high production cost,but also have many problems that hinder the further improvement of fuel cell performance.In view of the defects of Nafion membrane,acid-and alkali-doped polybenzimidazole?PBI?has become a research hotspot due to its performance.Phosphoric acid or potassium hydroxide doped PBI not only has good mechanical properties,but also has good thermal stability,chemical stability and humidity resistance,etc.In addition,its cost is much lower than Nafion membrane,so it has good application potential and prospect.In this paper,poly?2,5-dihydroxy-1,4-phenylpyridine-diimidazole??PIPD?was prepared as a membrane for the first time and the performance of its acid doped membrane was studied.A new polymer was prepared by adjusting the structure of the acid.The performance of the modified polymer membrane is test for fuel cell performance.Specific research contents are as follows:1)2,3,5,6-tetraminopyridine hydrochloride?TAP·3HCl·H₂O?and 2,5-dihydroxy-terephthalic acid?DHTA?are synthesized.The PIPD synthesized by condensation polymerization.Phosphoric acid-doped PIPD polymer membrane were prepared by solvent evaporation and drying method.FT-IR,SEM,TG,Tensile test and Fenton test are used to test the molecular structure,internal structure of the membrane,thermal stability,mechanical properties and antioxidant properties of the polymer.Finally,the proton transfer rate of the membrane was tested.2)TAP·3HCl·H₂O and 4,4'-diphenyl ether dicarboxylic acid were used to acquire a new polymer.The molecular structure of the polymer is characterized by FT-IR.The thermal properties of the polymer were test by TG and DMA.Then the membrane was modified by acid doping to prepare proton transport membrane,and the performance of the membrane in polymer electrolyte membrane is investigated by SEM,TG,tensile test,Fenton test,doping degree,water absorption rate,swelling degree and proton transfer rate.3)The prepared PPI polymer membrane is doping with potassium hydroxide to prepare anion transport membrane.The modified polymer molecular structure was measure by FT-IR.The performance and application prospect of the prepared anion transport membrane in alkaline fuel cell were explore by SEM-EDS,tensile test,alkali resistance test,Contact Angle test and anion transfer rate test.