Interactions of Anion-Exchange Resins with Polyacrylates in Atmosphere.

The interactions of polyacrylates (PAs with mean molecular weight of 4.5, 25, and 250 kDa; Na+ ,pa- ) with anion exchange resins in the Br- form (AXRs; -R+ ,Br- ) were studied under practical conditions by reaction stoichiometry and spectroscopy. The stoichiometric or an excess amount of PA(4.5 kDa) completely replaced Br- in the AXRs of the cross-linking degree of 2 or 8%, respectively, to give (-R+ ,pa- ), due to enhancement in selectivity of carboxylate group by multiple interactions. In contrast, PA(250 kDa) exchanged Br- only on the surface of AXRs and did not penetrate into the resins; CO2 was involved in the system to induce exchange with CO3 2- . Using the slightly acidic condition caused substantially no exchange by CO3 2- but induced coextraction of PA with proton as free Hpa. PA(4.5 kDa) once penetrating into the resin phase as (-R+ ,pa- ) or free Hpa was reversibly eluted under the appropriate conditions.