| 摘要 |
An ionomeric membrane formed of a sulphonic (per)fluorinated ionomer wherein the sulphonic groups are at the end of short side chains (SSC), said ionomer having: equivalent weight between 700 and 1600 g/eq; side chains of formula: -O-CF 2 -CF 2 -SO 3 - M + , wherein M is hydrogen or an alkaline metal;
said membrane having the following combination of properties: size variations, for both the orthogonal directions xy of the plane, lower than 15%, measured after dipping of the ionomeric membrane, dried at 105°C under vacuum for one hour, in demineralized water at 100°C for 30 minutes; the membrane, dipped at the temperature of 50°C for 22 hours in a water/ethanol mixture containing 40% by weight of alcohol, remains integral. |
