含氟PBI膜之質子傳導率研究

The Study of Proton Conductivity of Fluorine-containing Polybenzimidazoles Membranes

本研究利用3,3’-Diaminobenzidine (DAB)和2,2-Bis(4-carboxyphenyl)hexafluoropropane (HFA)兩種單體，以溶液縮聚法合成含氟聚苯咪唑(fluorine-containing polybenzimidazoles)，另外加入帶有磺酸根之單體5-Sulfoisophthalic Acid Monosodium Salt (SIPA)，合成磺化含氟聚苯咪唑(fluorine-containing sulfonated polybenzimidazoles)。因為聚苯咪唑(PBI) 在常見的有機溶劑中難以溶解，因此在聚合反應中加入含氟單體HFA，可擴大分子間距以提高其溶劑溶解度，聚合出的含氟聚苯咪唑得以溶解並製成薄膜；為提高材料介電性能，在聚合時同時加入帶有磺酸根之單體5-Sulfoisophthalic Acid Monosodium Salt (SIPA)，使磺化含氟聚苯咪唑薄膜擁有較佳的含水率及質子傳導率。從紅外線光譜儀分析可知成功合成含氟聚苯咪唑；從熱重損失分析可知此一系列薄膜的熱裂解溫度(Td)大約在540~565℃間，顯示了此複合膜具有耐高溫的特性；質子傳導率隨著磺化程度提高而增加，添加10.66 wt% SIPA的含氟PBI薄膜表現出高的導電率達7.61×10-4 S/cm；隨著磺化程度增加，吸水率亦有逐漸提升的趨勢，10.66 wt% SIPA含氟PBI薄膜吸水率可達15.10%。

In this study, fluorine-containing polybenzimidazole was synthesized by polycondensation of two monomers of 3,3'-Diaminobenzidine (DAB) and 2,2-Bis (4-carboxyphenyl) hexafluoropropane (HFA) . PBI is difficult to dissolve in common organic solvents. Fluoride monomers HFA in PBI are able to expanding the molecular spacing and to improve PBI's solvent solubility. To improve the material dielectric properties, another monomer 5-Sulfoisophthalic Acid Monosodium Salt (SIPA) was added to the polymerization solution. The fluorine-containing sulfonated polybenzimidazole film has better moisture content and proton conductivity. The infrared spectroscopy analysis shows that the success of synthesis of fluorinated polybenzimidazole chemical structure. Degredation temperature Td from TGA analysis is between 540 ~ 565 ℃, showing that the fluorine-containing PBI has high thermal properties. Water absorption tendency has gradually improved with the increases of SIPA content. The water absorption of fluoro-containing sulfonated PBI (with 10.66wt% SIPA) is 15.10%. The proton conductivity is increased with the degree of sulfonation, the results shows that the fluoropolymer (with 10.66wt% SIPA) films exhibited the conductivity up to 7.61 × 10-4 S / cm.