Antioxidant Properties of 2-Hydroxyethyl Methacrylate-Based Copolymers with Incorporated Sterically Hindered Amine

Abstract

A series of model linear copolymers of 2-hydroxyethyl methacrylate (HEMA) and a sterically hindered amine derivative [N-(2,2,6,6-tetramethyl-piperidin-4-yl)methacrylamide (HAS)] were synthesized and characterized. Scavenging activities of the copolymers against reactive oxygen species (peroxyl and hydroxyl radicals) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals were determined. It was found that copolymers with medium HAS content (3.5-4.0 mol %) were better scavengers than copolymers with lower and higher HAS content and also than polyHEMA and polyHAS homopolymers and the HAS monomer. Importantly, these copolymers compared favorably even to established low-molecular weight antioxidant standards (BHA and dexpanthenol). Monomer reactivity ratios were determined, and the microstructure of the copolymers was assessed. Subsequently, cross-linked copolymers in the powder and film forms with optimal HAS content were synthesized. Their scavenging activities against the three types of radicals were determined, revealing that these hydrogels are potent scavengers of reactive oxygen species.

Development of Poly(2-Methacryloyloxyethyl Phosphorylcholine)-Functionalized Hydrogels for Reducing Protein and Bacterial Adsorption

“…Initially, all hydrogels were fully dried to a constant weight before the equilibrium swelling. Subsequently, the fully dehydrated hydrogels were allowed to swell to equilibrium by immersion in phosphate-buffered saline (PBS, pH 7.4) and kept at room temperature for 24 h. It is widely known that a 24-h equilibration time is sufficient for fully swelling hydrogel samples [49,50]. Then, samples were removed from the PBS, excess surface water was blotted off with tissue paper, and the weights of the swollen hydrogels were recorded.…”

Carbohydrate-Modified Magnetic Nanoparticles for Radical Scavenging

“…Dn -number-average diameter (TEM); PDI -polydispersity index (TEM); Dh -hydrodynamic diameter (DLS); PI -polydispersity (DLS). Finally, γ-Fe 2 O 3 &SiO 2 -G-ASA free-radical scavenging activity in SBB buffer was spectrophotometrically determined (Poláková et al 2015). SBB buffer was selected for these experiments as it prevents the particle agglomeration, in contrast to phosphate-buffered saline, where the particles aggregate due to high affinity of phosphate ions to iron oxides.…”

Multifunctional amphoteric heteropolymer for chromium free sustainable leather process

“…Hydroxyethyl methacrylate (HEMA) is the most commonly used monomer for synthesizing a variety of copolymers of acrylic ester. The monomer possesses a hydroxyl group, which is modified for the synthesis of carboxylic and long‐chain hydrophobic monomers 20,21 . In our previous study amphoteric hetero polymers were synthesized and used in a metal‐free tanning process, resulting in the leather with moderate shrinkage temperature 22 .…”