Use of sulfonated bead polymers of styrene, crosslinker and vinylpyridine as reversible cation exchange resins in co- or counter-current flow systems, e.g. for dematerializing process water for use as boiler feed

摘要

Sulfonated bead polymers derived from a monomer mixture containing 67-99.45 wt% styrene, 0.05-20 wt% crosslinker and 0.5-8 wt% vinylpyridine are used as cation exchange resins for the reversible exchange of cations in co-current and/or counter-current flow systems. The use of special cation exchange resins for the reversible exchange of cations in co-current and/or counter-current flow systems is claimed. These resins are obtained by: (i) forming a suspension of seed polymer and monomer mixture in a continuous aqueous phase (the seed polymer being produced by atomizing a mixture of monomers (A) and (B) or (A), (B) and (C) in an aqueous phase and then polymerizing the mixture), or a hetero- or homo-disperse suspension of monomer mixture by stirring or atomizing in an aqueous phase; (ii) polymerizing the monomer mixture in the seed polymer or the hetero- or homo-disperse suspension to form a copolymer; and (iii) functionalist the copolymer by sulfonation. The monomer mixture comprises: (A) 67-99.45 wt% of styrene; (B) 0.05-20 wt% of crosslinker; (C) 0.5-8 wt% of vinylpyridines; and (D) 0.1-1.1 parts by weight (pts. wt.) of polymerisation initiator to 100 pts. wt. of (A) or (A+B+C).