Interactions of Anion-Exchange Resins with Polyacrylates in Atmosphere

Abstract

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; CO was involved in the system to induce exchange with CO. Using the slightly acidic condition caused substantially no exchange by CO 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.

Slow, Mid-saturated Exchanges by Large Anions on Resins due to Increase in Independency of Exchange Sites with Cross-Linking

“…This assures no protonation of each AA nor interference by carbon dioxide. 17 Each 0.1 cm 3 solution was sampled and subjected to UV-VIS spectroscopy for determination of equilibration time. The equilibrium studies were similarly performed by changing the concentration of each AA (CAA/mol L -1 ; total amount of AA/mmol: TAAA = CAA × 20).…”