Crosslinking of hydroxamic acid copolymers through iron chelation

Abstract

Polymers bearing widely spaced hydroxamic acid (HA) groups were synthesized by copolymerization of the iV-hydroxysuccinimide ester of iV-methacryloyl-d-alanine with acrylamide, followed by treatment with methylhydroxylamine. The HA content of the three copolymers was measured spectrophotometrically, using the 504 nm absorption of the 1:1 HA-Fem complex. The copolymers contained 0.749, 0.259, and 1.80 mol % HA units, and their intrinsic viscosities in water at 30 °C were 0.58,1.86, and 0.52 dL/g, respectively. The effect of the HA:Fe ratio and the overall polymer concentration on the intrinsic viscosity was studied. At high concentrations of polymer, addition of iron (III) caused [ ] to increase up to a maximum at an HA:Fe ratio of 3:1. Below the 3:1 ratio, [ ] decreased rapidly back to the value of the original solution. At low concentrations of polymer, addition of iron caused a decrease in [ ] to a minimum at an HA:Fe ratio of 3:1. Below 3:1, [ ] increased back to the values of the original solution. At higher concentrations, the probability of intermolecular complexation is high, resulting in cross-linking and increasing [??]. At lower

Biomimetic design of chelating interfaces

“…To the best of our knowledge, there are no commercially available monomers containing HA groups that are suitable for photoinitiated graft polymerization. The commonly used approach to prepare synthetic PHA polymers is by the hydroxylamidation reaction of active moieties including acrylic ester, 5,28 acrylamide, 24,25 acrylonitrile, 32 and acid chloride. 4,17,26 Hence, we herein chose methyl acrylate, which contains an acrylic ester group, as the monomer to covalently graft a high density of acrylic ester active groups from the PP substrate surface in the first step.…”

“…The high specificity and affinity of the functional groups (e.g., HA) in siderophores for metal chelation has inspired researchers to design biomimetic metal chelating polymers [Figure (B)]. The majority of published research in this area has focused on synthesis of free macromolecules, hydrogels, and resins with biomimetic metal chelating functionality . However, the ability to impart siderophore‐mimetic chelating functionality to the surface of solid supports would enable significant improvements in recovery and reuse of chelating materials, and expand their societal and commercial impact (e.g., separation process for wastewater treatment, active packaging applications, etc.).…”

“…The majority of published research in this area has focused on synthesis of free macromolecules, hydrogels, and resins with biomimetic metal chelating functionality. 4,5,17,[24][25][26][27][28] However, the ability to impart siderophore-mimetic chelating functionality to the surface of solid supports would enable significant improvements in recovery and reuse of chelating materials, and expand their societal and commercial impact (e.g., separation process for wastewater treatment, active packaging applications, etc.). Further, by manipulating only the surface chemistry, desirable bulk material properties (optical, thermo-mechanical, magnetic, and economic) can be maintained, which can further expand the application of such materials.…”

Synthesis of Bipyridyl-Branched Polyoxazoline and Its Gelation by Means of Metal Coordination

“…Concerning the conversion from intermolecular complex (gel) to intramolecular one, Winston has pointed out in the case of hydroxamic acid copolymers and iron(III) ion. 9 Thus, the interconversion from the gel to the polymer in 9b and 9c, can be rationalized. On the other hand, Fe(II) and Ru(III) (vide infra) complexes (9a, 9d) are known to be so inert that the formed intermolecular networks are expected to disappear very slowly or do not at all.…”

“…In the case of a watersoluble polymer, Winston et al reported the preparation and the gelation of the hydroxamic acid derivated poly(acrylamide). 9 We wish to report here the preparation of the PAEI hydrogel through the coordination between the pendant ligand group and metal ions.…”