Supercritical carbon dioxide application using hydantoin acrylamide for biocidal functionalization of polyester.

Biocidal functionalization in polyester fibers is a really tough challenge because of the lack of tethering groups. This study indicated supercritical carbon dioxide application using -halamine would be an alternative solution for obtaining antibacterial function on the polyester surface. Firstly, -(2-methyl-1-(4-methyl-2,5-dioxo-imidazolidin-4 yl)propan-2 yl)acrylamide was synthesized and applied to the polyester in supercritical carbon dioxide medium, at 120 °C, 30 MPa for different processing times.

Inter- and intramolecular mechanisms for chlorine rearrangements in trimethyl-substituted N-chlorohydantoins.

The antimicrobial compounds 1-chloro-3,5,5-trimethylhydantoin and 3-chloro-1,5,5-trimethylhydantoin (1 and 2, respectively) have been synthesized and examined via a joint experimental and computational study. The measured rate of loss of oxidative chlorine in the absence and presence of exposure to UVA irradiation determined 2 to be less stable than 1. An interesting migration reaction was observed during UVA irradiation that featured the production of chlorine rearrangement and dechlorinated compounds.

N-halamine copolymers for use in antimicrobial paints.

A series of copolymers containing units of a novel hydantoinylacrylamide and the sodium salt of 2-(acrylamido)-2-methylpropanesulfonic acid have been synthesized. The homopolymer of the hydantoinylacrylamide compound was insoluble in water, while the copolymers with the sulfonic acid sodium salt were water-dispersible/soluble, with the solution becoming completely transparent when the feed ratio for the copolymer contained 7 parts of the hydantoin moiety to 3 parts of the sodium sulfonate moiety. The polymers were added into a commercial water-based latex paint, and upon drying, the painted surfaces treated with the water-miscible copolymers were rendered antimicrobial following chlorination with dilute household bleach.

Polymeric antimicrobial N-halamine epoxides.

A new N-halamine copolymer has been prepared, characterized, and evaluated for antimicrobial efficacy, stability toward hydrolyses, and stability toward UVA degradation when covalently bound to cellulose fibers. A copolymer of 3-chloro-2-hydroxypropylmethacrylate and glycidyl methacrylate was coated onto cotton, and, after curing, was treated with an aqueous solution containing the potassium salt of 5,5-dimethylhydantoin to form a coating which became antimicrobial upon exposure to househod bleach (sodium hypochlorite). The coating inactivated S.

N-halamine biocidal coatings via a layer-by-layer assembly technique.

Two N-halamine copolymer precursors, poly(2,2,6,6-tetramethyl-4-piperidyl methacrylate-co-acrylic acid potassium salt) and poly(2,2,6,6-tetramethyl-4-piperidyl methacrylate-co-trimethyl-2-methacryloxyethylammonium chloride) have been synthesized and successfully coated onto cotton fabric via a layer-by-layer (LbL) assembly technique. A multilayer thin film was deposited onto the fiber surfaces by alternative exposure to polyelectrolyte solutions. The coating was rendered biocidal by a dilute household bleach treatment.

Mechanism of photolytic decomposition of N-halamine antimicrobial siloxane coatings.

Generally, antimicrobial N-halamine siloxane coatings can be rehalogenated repetitively upon loss of their biocidal efficacies, a marked advantage over coatings containing other antimicrobial materials. However, the N-halamine materials tend to slowly decompose upon exposure to ultraviolet irradiation as in direct sunlight. In this work the mechanism of photolytic decomposition for the N-halamine siloxanes has been studied using spectroscopic and theoretical methods.

Antimicrobial modification of polyester by admicellar polymerization.

The N-halamine monomer 3-(4'-vinylbenzyl)-5,5-dimethylhydantoin (VBDMH) was synthesized and employed to form thin films on the surfaces of polyester fibers by surface polymerization with the aid of a cationic surfactant. The coated samples were characterized by FTIR and SEM. The thin film coatings could be rendered biocidal by exposure to dilute sodium hypochlorite.

Why does Kevlar decompose, while Nomex does not, when treated with aqueous chlorine solutions?

Kevlar and Nomex are high-performance polymers which have wide varieties of applications in daily life. Recently, they have been proposed to be biocidal materials when reacted with household bleach (sodium hypochlorite solution) because they contain amide moieties which can be chlorinated to generate biocidal N-halamine functional groups. Although Nomex can be chlorinated without any significant decomposition, Kevlar decomposes under the same chlorination conditions.