Synthesis and Characterization of Anionic Exchange Resins with a Gradient in Polymer Composition for the PS-co-DVB/PDEAMA-co-DVB System

Summary Anionic exchange resins with a gradient in polymer composition were prepared in two stages. After P(S-co-DVB) suspension beads were obtained, N,N-diethylaminoethyl methacrylate monomer was let to diffuse into the beads at 25 °C, and immediately photopolymerized to fix the gradient polymer composition with high surface concentration of ion exchanger. Chemical composition through the radial position was estimated by means of a mathematical algorithm and using UV spectroscopy. Resin characterization included particle size distribution, “settled” density and total anion exchange capacity, following ASTM D-2187. Values were compared with a porous commercial resin (Amberlite IRA900RF Cl). Since non porous structure with high ion exchange capacity resins were obtained, useful resins for ion exchange with long term stability can be prepared with this methodology.