| 摘要 |
The -CF2OR groups in a starting copolymer comprising random-CX2CX2 units and
<CHEM>
units, where the four X's are four fluorines or three fluorines and one chlorine, n is 0 or 1 and R is CH3 or C2H5, are converted into -COZ groups, where Z is F or OR min and R min is CH3 or C2H5, by treatment with a strong acid at a temperature of at least 50 DEG C but below the decomposition temperature of the reactants and product. The product copolymer can be hydrolyzed to give copolymers having carboxylic groups which are useful, e.g. in the form of a permionic membrane, for separating the compartments of a chloralkali cell. |
