Stabilization of vulcanized polyethylene

Losev, Yu. P.; Paushkin, Ya. M.

doi:10.1002/app.1992.070450902

Cited by 5 publications

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“…We report the synthesis and H 2 S release of several water-soluble, thiol-mediated, and burst release H 2 S donors based on the functional groups diaminodisulfides and dialkoxydisulfides. These functional groups are poorly studied in organic chemistry, although there are reports of chemicals with these functional groups investigated for their antibacterial properties. − Most applications of diaminodisulfides are for use as vulcanizing agents because they break down at elevated temperatures of >150 °C to release radicals . Heterosubstituted disulfides (XSSX, X = R 2 N and RO) have not been reported to release H 2 S yet stand to join the class of H 2 S donors.…”

Section: Introductionmentioning

confidence: 99%

“…40−42 Most applications of diaminodisulfides are for use as vulcanizing agents because they break down at elevated temperatures of >150 °C to release radicals. 43 Heterosubstituted disulfides (XSSX, X = R 2 N and RO) have not been reported to release H 2 S yet stand to join the class of H 2 S donors. Water-soluble versions of these heterosubstituted disulfides were synthesized to investigate their release of H 2 S in aqueous systems with current H 2 S sensing amperometry technology.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and Hydrogen Sulfide Releasing Properties of Diaminodisulfides and Dialkoxydisulfides

Grace

Bowden

2021

ACS Omega

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Heterosubstituted disulfides are an understudied class of molecules that have been used in biological studies, but they have not been investigated for their ability to release hydrogen sulfide (H 2 S). The synthesis of two sets of chemicals with the diaminodisulfide (NSSN) and dialkoxydisulfide (OSSO) functional groups was reported. These chemicals were synthesized from commercially available sulfur monochloride or a simple disulfur transfer reagent. Both the diaminodisulfide and dialkoxydisulfide functional groups were found to have rapid rates of H 2 S release in the presence of excess thiol. The release of H 2 S was complete with 10 min, and the only byproducts were conversion of the thiols into disulfides and the amines or alcohols originally used in the synthesis of the diaminodisulfide or dialkoxydisulfide functional groups. These results will allow the design of H 2 S releasing chemicals that also release natural, biocompatible alcohols or amines. Chemicals with the diaminodisulfide and dialkoxydisulfide functional groups may find applications in medicine where a controlled, burst release of H 2 S is needed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis and Hydrogen Sulfide Releasing Properties of Diaminodisulfides and Dialkoxydisulfides

Grace

Bowden

2021

ACS Omega

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“…The diaminosulfide functional group has the general structure of R 2 N–S–NR 2 as shown in Figure . Small molecules with this functional group have been synthesized using sulfur transfer reagents such as those molecules shown in Figure b. − The most prominent applications of small molecules with diaminosulfides have been in the chemical industry for the high-temperature vulcanization of rubber and in the construction of polymers with benzo[1,2,5]thiadiazoles along the backbone (Figure c) . Polymers that incorporate benzo[1,2,5]thiadiazoles have found uses as semiconductors, fluorophores, and photoactive components in organic solar cells due to their interesting electro-optical properties. − These polymers link the monomers through carbon–carbon bonds as shown in Figure c rather than through the nitrogen or sulfur atoms as in poly(diaminosulfide)s. Surprisingly, no one has used diaminosulfides to bond monomers together as shown in Figure a, and these polymers are the focus of this report.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of the First Poly(diaminosulfide)s and an Investigation of Their Applications as Drug Delivery Vehicles

et al. 2012

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This paper reports the first examples of poly(diaminosulfide)s that were synthesized by the reaction of a sulfur transfer reagent and several secondary diamines. The diaminosulfide group has the general structure of R2N-S-NR2 and, although it has been used in the synthesis of small molecules, it has never been utilized in the synthesis of macromolecules until this report. A series of poly(diaminosulfide)s were synthesized at elevated temperatures, and the molecular weights of the polymers were as high as 12,400 g mol−1 with conversions for the polymerization reaction up to 99%. The rate constants for the transamination reactions that lead to the polymers were measured in several solvents to provide an understanding the reaction conditions necessary to polymerize the monomers. The degradation of diaminosulfides were studied in D2O, C6D6, CD3OD, CDCl3, and DMSO-d6/D2O to demonstrate that they were very stable in organic solvents but degraded within hours under aqueous conditions. These results clearly demonstrated that diaminosulfides are very stable in organic solvents under ambient conditions. Poly(diaminosulfide)s have sufficient stabilities to be useful for many applications. The ability of these polymers to function as drug delivery vehicles were studied by the fabrication of nanoparticles of a water-insoluble poly(diaminosulfide) with a dye. The microparticles were readily absorbed into human embryonic 293 cells and possessed no measureable toxicity towards these same cells.

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“…[218][219][220] The most prominent applications of small molecules with diaminosulfides have been in the chemical industry for the high temperature vulcanization of rubber and in the construction of polymers with benzo [1,2,5]thiadiazoles along the backbone (Figure A-1c). 221 Polymers that incorporate benzo [1,2,5]thiadiazoles have found uses as semiconductors, fluorophores, and photoactive components in organic solar cells due to their interesting electro-optical properties. [222][223][224][225][226][227][228][229][230] These polymers link the monomers through carbon-carbon bonds as shown in Figure A-1c 231 Inorganic functional groups are interesting targets for polymer synthesis because they can be expected to have new reactivities that differ from those of organic functional groups and they have the potential to act as ligands for metals.…”

Section: Introductionmentioning

confidence: 99%

Poly(disulfidediamines)

Graf¹

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The turnovers of a gold(III) chloride catalyst were increased by 3,300% with the addition of several equivalents of (2,2,6,6-tretramethyl-piperidin-1-yl)oxy and catalytic amounts of copper(II) chloride. A three component coupling reaction between piperidine, phenylacetylene, and benzaldehyde yielded a propargylamine in quantitative conversions and isolated yields when gold(III) chloride was added in catalytic amounts, but the gold catalyst decomposed and had little to no reactivity when a second set of piperidine, phenylacetylene, and benzaldehyde were added after the reaction was complete. The addition of (2,2,6,6-tretramethyl-piperidin-1-yl)oxy and copper(II) chloride to reactions with gold(III) chloride maintained the catalytic activity of the gold for up to 33 cycles. This result demonstrates a new way to greatly increase the turnovers of a gold(III) chloride catalyst with the addition of inexpensive, commercially available reagents. The synthesis and some of the physical properties of the first poly(disulfidediamines) are reported. These polymers were synthesized in high yields and with conversions up to >98% by reactions between secondary diamines and a new disulfide monomer. The disulfide monomer was synthesized in two steps without the need for column chromatography. The polymerizations were robust and completed at room temperature, under ambient atmospheric conditions, and in solvents that were used as purchased. These polymers were stable, but they rapidly decomposed under acidic, aqueous conditions to release hydrogen sulfide. A method for quantifying the hydrogen sulfide released was also developed.

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Stabilization of vulcanized polyethylene

Abstract: SYNOPSISSome polyaminedisulphides were studied as thermal stabilizers of polyethylene vulcanized by dicumyl peroxide. The effects of temperature, time, and concentration were investigated. A reaction mechanism is suggested.

Cited by 5 publications

References 0 publications

Synthesis and Hydrogen Sulfide Releasing Properties of Diaminodisulfides and Dialkoxydisulfides

Synthesis and Hydrogen Sulfide Releasing Properties of Diaminodisulfides and Dialkoxydisulfides

Synthesis of the First Poly(diaminosulfide)s and an Investigation of Their Applications as Drug Delivery Vehicles

Poly(disulfidediamines)

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