| 초록 |
Sulfonated polymer membranes are used in several electrochemical processes such as in cloro-alkali production, water electrolysis, electrodialysis and polymer electrolyte membrane fuel cells. In these applications, the membrane must have a high thermal, chemical, and electrochemical stability as well as mechanical resistance at the operating conditions. In addition, for water electrolysis and in fuel cell applications, very low gas permeability between hydrogen or methanol and oxygen, and for this reason the aromatic polymers having rigid packing structures have been used as backbone polymers for sulfonation. In the present study, sulfonated aromatic polymers such as sulfonated polysulfone and polyimide were prepared via direct and mild sulfonation method. Degree of sulfonation (DS) and ion exchange capacity (IEC) in each sulfonated polymers were measured by using the elemental analysis, the titration method, and the ion-conductivity method. Effect of water uptake on the IEC values of sulfonated polymers was studied using the dynamic vapor sorption apparatus. Thermal and chemical stability of each sulfonated polymers were investigated by means of thermal gravimetric analysis (TGA) coupled with mass spectroscope (MS) and accelerated peroxide test, changing DS and IEC value. |
