| 초록 |
Sulfonated polyimides had been utilized and studied widely as available materials in chloro-alkali electrolysis, cationic exchange resins, proton exchange membrane fuel cell (PEMFC) and so on. However, a slow decrease in performance during experiments had been reported, which could be attributed to a loss of ionic conductivity related to either a continuous dehydration or polymer degradation. One of main reasons to account for degradation of sulfonated polymers is the hydrolysis leading to polymer chain scission and decrement of molecular weight. Therefore, the objective of our study was to investigate possible imide cycle and additional ester bond cleavage connected with SO3H presence under hydrated condition. In order to confirm and obtain as clear information as possible about breakages of bonds from 1H and 13C NMR and IR spectroscopic analyses, our study was performed by model compound. Consequently, model compounds with both phthalic and naphthalenic imide ring and ester bonds were synthesized to evaluate the hydrolysis stability of sulfonated polyimide. The experiments were performed for prepared model compounds before and after aging in deionized water at 60℃ and were terminated by lyophilization technique. The aging products were finally analyzed by NMR and IR spectroscopy. |
