Abstract: Several kinds of snake-cage resins containing both carboxylic and quaternary ammonium groups were synthesized from cage resin with 7 % crosslinking. The influence of the crosslinking degree on retardation capacity and separation ability has been studied. These resins were used to separate the water-soluble nonvolatile impurities (NVI) from the spinning SQ lvent of polyacrylonitrile-sodium thiocyanate solution. Satisfactory results were achieved.

Key words: Snake-cage resin, Ion retardation, Sodium thiocyanate solution. Spinning solvent of polyacrylonitrile