摘要 |
An ion exchange membrane of a fluorinated polymer which contains sulfonyl groups, wherein the sulfonyl groups on one surface of the membrane are in the form of N-monosubstituted sulfonamide groups formed from a di- or polyamine, is treated by heating at a temperature of 100 DEG to 160 DEG C. for a time of at least 15 minutes. The resulting membrane is useful as the membrane in a chloralkali electrolysis cell, and permits operation of such cells at high current efficiency over extended periods of time.
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