Resins having improved exchange kinetics
AssigneeThe Dow Chemical Company
InventorWilliam C. Pike
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Abstract
Disclosed are novel ion-exchange and chelate-exchange resins having improved exchange kinetics for separating chemical species from liquids. The resins are prepared from copolymer beads consisting of a monovinyl aromatic monomer and a cross-linking monomer. The copolymer beads are functionalized such that weak-base exchange moieties are substituted at haloalkylated sites which are most accessible to diffusion into the beads, while hydrophilic, strong-base exchange moieties are substituted at haloalkylated sites which are least accessible to diffusion. The resins have improved exchange kinetics due to shortened diffusion path lengths for the chemical species being separated and improved diffusion into the resin beads due to the hydrophilic, strong-base exchange moieties.
Claims13
A process having improved exchange kinetics for separating chemical species from a liquid containing the chemical species in solution, the process comprising:
- (a) contacting the liquid with a resin such that the chemical species are retained thereby, the resin comprising cross-linked copolymer beads having weak-base exchange moieties substituted at haloalkylated sites which are most accessible to diffusion and hydrophilic, strong-base exchange moieties substituted at haloalkylated sites which are least accessible to diffusion;
- and
- (b) eluting the retained chemical species from the resin with a regenerating agent.
Dependencies are inferred from the claim text.