Synthesis and characterization of interpenetrating polymer network resins, polymer foam-supported ligands, and polystyrene/polyphenolic ion-complexing reagents

A variety of class II (ion exchange/coordination) ion-selective polymers was synthesized and characterized. The polymers belong to the category of dual mechanism bifunctional polymers (DMBPs). A series of resins were prepared by the formation of interpenetrating polymer networks (IPNs). The IPN resins consisted of poly(methyl methacrylate) as network I and poly(N-vinylimidazole-co-ethyl acrylate) in the ratios of 1:0, 0.7:0.3, 0.5:0.5, 0.3:0.7, and 0:1 as network II. The microenvironments of the resins were evaluated through the determination of binding constants with Cu(ll), Co(ll), and phenylphosphinic acid. The binding constants were determined using double rectangular hyperbolic equations with the aid of Scatchard plots. A series of IPN resins containing poly(N-vinylimidazole-co-ethyl acid) as network II were also synthesized to introduce an ion-exchange mechanism into the polymer. Poly(vinylbenzyl chloride)-based rigid foams were functionalized with phosphonic acid ligands. The foams were evaluated for enhanced metal ion complexation, relative to gel and macroreticular beads, because of their highly macroporous network. The foams were also functionalized with phosphonate ester ligands. The increased porosity of the foams allows a greater accessibility of the metal ions to the phosphonate ester ligands than with the gel or macroreticular beads. Cesium(l) selective resins were prepared utilizing a phenol-formaldehyde condensation reaction. Phenol-formaldehyde chains were grafted onto poly(vinylbenzyl chloride)-based and diphosphonate-based resins. The resins complexed Cs(l) from sodium hydroxide solutions, and had distribution coefficients greater than 400 mL/g.