Base-functionalized polymeric chemisorbents for succinic acid recovery from aqueous solution

New base-functionalized polymers are synthesized and assessed for their ability to chemisorb succinic acid (SA) from dilute aqueous solution. A hydrogel comprised predominantly of poly(2-N,N-dimethylaminoethylacrylamide) absorbs 0.17 g·SA /g·polymer, representing just 21% of the maximum theoretical yield. The lower-than-expected basicity is attributed to confinement of polymer-bound amine functionality by the swollen crosslink network, which inhibits the solvation needed to stabilize ammonium carboxylate ion pairs. These gel effects are avoided by synthesizing a 1-vinyl-3-dodecylimidizolium based polyionic liquid (PIL) bearing a hydroxide counter ion. This linear, water-insoluble PIL absorbs 0.20 g·SA /g·polymer, and functions effectively at the near-neutral pHs required of most biocatalysts. As such, the material is sufficiently basic to extract succinic acid during its bioproduction, while also facilitating feed-back control of aqueous solution pH. [Display omitted] •Amine basicity within hydrogels is reduced by functional group confinement.•Polyionic liquids bearing a hydroxide counter anion are stable and basic.•Organic acid chemisorption can be accomplished at neutral pH.