| 摘要 |
Porous ion-exchange resins are prepared by (1) dissolving a preformed linear polymer or copolymer in a mixture of monomeric styrene and divinylbenzene, (2) curing the mixture containing the preformed polymer or copolymer, and, if the polymer or copolymer is not saponifiable, (3a) solvent-extracting the polymer or copolymer from the cured product and there-after, depending on the desired type of ion exchange resin, either sulphonating or chloromethylating and aminating the cured product, and, if the polymer or copolymer is saponifiable, (3b) depending upon the desired type of ion exchange resin, either sulphonating or chloromethylating and aminating the cured product, and thereafter treating the sulphonated or chloromethylated and aminated product with an alkaline solution to remove the polymer or copolymer therefrom, the polymer or copolymer used in step (1) being of a type which does not give rise to a graft copolymer with the mixture of monomeric styrene and divinyl benzene in the curing step (2). In examples the polymers used are a copolymer of vinyl acetate and diethyl maleate, which is removed by saponification, and polystyrene, which is removed by solution in benzene. |
