Synthesis and sorption properties of a polyampholyte

Synthesis of Water‐Soluble Oligomers From Imidazole, Ethyleneglycol Diglycidyl Ether, and Methacrylic Acid. An Insight Into the Chemical Structure, Aggregation Behavior and Formation of Hollow Spheres

“…The probable structure of the water‐soluble diblock oligomers is consistent with the synthetic strategy applied, since IM reacts with EGDE in a first step forming blocks of EGDE‐IM adducts, followed by the addition of MAA (where ester groups could be formed) and a final treatment with benzoyl peroxide to polymerize vinyl groups from free and esterified MAA. This structure would be configurationally different from the non‐soluble statistic polyampholytes obtained by a one‐pot mixture of the reagents and reported in previous articles, but keeping most functionalities. In non‐soluble polyampholytes, polyetherification would prevail over EGDE‐IM adducts.…”

“…In the first case, since IMH + MA – ion pairs are formed prior to EGDE addition, polyetherification is faster than adduct formation due to the low concentration of IM monomer . The higher amount of polyether leads to polyampholytes that are non‐soluble in most solvents . Instead, when the Poly(EGDE‐IM) hydrogel is synthesized, adduct formation (Scheme , stage A) prevails over polyetherification (Scheme , stage B), bringing a highly solvated integral polyelectrolyte with positive electric charge even at pH 11.0 due to disubstituted IM (IM + ) units …”

“…The volumes of the HCl standard solution at the inflection points were used to calculate the density of protonatable sites, which was determined to be 3.6 mmol · g −1 (S.D. : 0.3), a value significantly higher than the density of titrable sites in the non‐soluble polyampholyte containing the same monomers . Details about the effects of the interaction between charged groups on the apparent acid dissociation constant value are presented in Figure S6 in Supplementary data.…”

“…This result particularly contrasted the expected anti‐fouling feature mentioned above: in our development, the homogeneous molecular level of positive and negative charges in the feed mixture enhanced protein adsorption. The uptake of biomolecules was observed at pH values above the IEP, where both molecules (polyampholyte and protein) bore negative net charge . The presence of positive and negative domains in both compounds would account for an interaction between dipoles.…”

“…There are many successful examples where the resulting features of the polymeric material are strongly related to the proportion of ionizable functional groups in the feed ratio. Using the one‐pot synthetic strategy of random copolymerization, our group has previously obtained non‐soluble polyampholytes by mixing methacrylic acid (MAA) with imidazole (IM) or derivatives around the charge balance point at high concentration, plus the addition of ethyleneglycol diglycidyl ether (EGDE) . The epoxy groups of the last monomer were opened up by both carboxylic groups of MAA and the pyridine‐type nitrogen of the N ‐heterocycle, and a peroxide‐initiated radical polymerization of MAA segments covalently bound to EGDE finally gave a statistical copolymer, non‐soluble in water.…”