Synthesis and membrane properties of polybenzimidazole

• Main Authors: Chih-Hao Chiu, 邱志豪
• Other Authors: T. L. Yu
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/38308868350246961421

碩士 === 元智大學 === 化學工程學系 === 92 === In this study, polybenzimidazole (PBI) was synthesized from 3,3’-diamino benzidine and isophthalic acid. The structure of polybenzimidazole was determined by FTIR and 13CNMR. The polybenzimidazole had an inherent viscosity of 1.29 dL/g (0.500 g/dL in 98% sulfuric acid solution). Thermal gravimetric analysis (TGA) showed that there was a 12.5% weight lose as temperature was raised from 30℃ to 200℃, due to the evaporation of water. The film of PBI was prepared by casting the PBI/dimethylacetamide solution and evaporated the solvent under 120℃ and then the membrane was annealed at 200℃. The physical and chemical properties of PBI film were investigated using material testing machine, acid doping level, and conductivity measurements. According to the experimental results, it is shown that increasing the annealing time at 200℃ increases the acid doping level. The conductivity of acid-doped PBI is influenced by doping level, environmental temperature and relative humidity.