reactions of antioxidants with molecular oxygen part ii

reactions of antioxidants with molecular oxygen. part ii

Reactions of antioxidants with molecular oxygen. Part II

Reactions of antioxidants with molecular oxygen. Part I. 2,2′-methylene-bis(4-methyl-6-tert-butylphenol) in silicone matrix Polym Degrad Stab , 96 ( 2011 ) , pp. 220 - 225

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reactions of antioxidants with molecular oxygen. part ii

Reactions of antioxidants with molecular oxygen. Part II

R. NAVARRO, Ludmila AUDOUIN, Jacques VERDU - Reactions of antioxidants with molecular oxygen. Part II. Isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate in silicone matrix - Polymer Degradation and Stability - Vol. Volume 96, Issue 5, p.Pages 965-973 - 2011 Any correspondence concerning this service should be sent to the repository

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reactions of antioxidants with molecular oxygen. part ii

Reactions of antioxidants with molecular oxygen. Part II

Request PDF | Reactions of antioxidants with molecular oxygen. Part II. Isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate in silicone matrix | The study of oxidation kinetics of isooctyl-3

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reactions of antioxidants with molecular oxygen. part i. 2,2

Reactions of antioxidants with molecular oxygen. Part I. 2,2

A part of the stabiliser interacts with polymer transformation products, whereas another part of the stabiliser can be lost by physical migration out of the polymer or direct interaction with molecular oxygen . The direct reaction of antioxidant with oxygen has been discussed in several articles , , . In the case of phenolic antioxidants, the

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reactions of antioxidants with molecular oxygen. part ii

Reactions of antioxidants with molecular oxygen. Part II

Reactions of antioxidants with molecular oxygen. Part II. Isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate in silicone matrix

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reactions of antioxidants with molecular oxygen. part i. 2,2

Reactions of antioxidants with molecular oxygen. Part I. 2,2

The reaction of 2,2′-methylene-bis(4-methyl-6-tert-butylphenol) stabiliser with oxygen was studied in an inert substrate at 80-120°C temperature under 0.02-3.0 MPa oxygen pressure ranges. UV/VIS spectrophotometry and Gel Permeation Chromatography were used to follow the antioxidant consumption and the formation of oxidation products.

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reactions of antioxidants with molecular oxygen. part iii

Reactions of antioxidants with molecular oxygen. Part III

Reactions of antioxidants with molecular oxygen. Part III: Influence of phenolic stabiliser structures on their oxidation in an inert matrix R. Navarro, Ludmila Audouin, Jacques Verdu To cite this version: R. Navarro, Ludmila Audouin, Jacques Verdu. Reactions of antioxidants with molecular oxygen.

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reactions of antioxidants with molecular oxygen. part iii

Reactions of antioxidants with molecular oxygen. Part III

The reaction of 2,2′-methylene-bis(4-methyl-6-tert-butylphenol) stabiliser with oxygen was studied in an inert substrate at 80–120 °C temperature under 0.02–3.0 MPa oxygen pressure ranges.

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reactions of antioxidants with molecular oxygen. part i. 2,2

Reactions of antioxidants with molecular oxygen. Part I. 2,2

The reaction of 2,2′-methylene-bis(4-methyl-6-tert-butylphenol) stabiliser with oxygen was studied in an inert substrate at 80-120°C temperature under 0.02-3.0 MPa oxygen pressure ranges. UV/VIS spectrophotometry and Gel Permeation Chromatography were used to follow the antioxidant consumption and the formation of oxidation products.

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the unusual reaction of semiquinone radicals with molecular

The Unusual Reaction of Semiquinone Radicals with Molecular

Hydroquinones (benzene-1,4-diols) are naturally occurring chain-breaking antioxidants, whose reactions with peroxyl radicals yield 1,4-semiquinone radicals. Unlike the 1,2-semiquinone radicals derived from catechols (benzene-1,2-diols), the 1,4-semiquinone radicals do not always trap another peroxyl radical, and instead the stoichiometric factor of hydroquinones varies widely between 0 and 2

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reactions of antioxidants with molecular oxygen. part iii

Reactions of antioxidants with molecular oxygen. Part III

The reaction of 2,2′-methylene-bis(4-methyl-6-tert-butylphenol) stabiliser with oxygen was studied in an inert substrate at 80-120°C temperature under 0.02-3.0 MPa oxygen pressure ranges. UV/VIS spectrophotometry and Gel

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free radicals: properties, sources, targets, and their

Free Radicals: Properties, Sources, Targets, and Their

Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS) In general pro-oxidants/oxidants are termed as ROS/RNS. The most important free radicals produced during metabolic reactions are radicals derived from oxygen, ROS. Both the ROS and RNS can be classified into two groups of compounds namely; radicals and non-radicals (see Table 1

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degradation of ethylene – propylene elastomers in the

Degradation of ethylene – propylene elastomers in the

The phenolic antioxidants are breaking chain stabi-lizers and they act especially in the previous stage of oxidation when they are not depleted. The distribu-tion of degrading products seems to be influenced by the reactivity of antioxidants. The reaction of molecular oxygen with free radicals requires a low activation energy so that this

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mechanism of the formation of electronically excited species

Mechanism of the Formation of Electronically Excited Species

2.1.1. Formation . Superoxide anion radical is formed by the one-electron reduction of molecular oxygen (Figure 1, reaction 1).The one-electron reduction of molecular oxygen occurs in the mitochondria during cellular respiration, in the chloroplast during the light reaction of photosynthesis and in the membrane-bound enzyme complex NADPH oxidase during the oxidative burst.

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the unusual reaction of semiquinone radicals with molecular

The Unusual Reaction of Semiquinone Radicals with Molecular

They show that the reaction of O2 with 2,5-di-tert-butyl-1,4-semiquinone radical (used as model compound) has a rate constant of 2.4 ( 0.9 × 105 M-1 s-1 in acetonitrile and as high as 2.0 ( 0.9 × 106 M-1 s-1 in chlorobenzene, i.e., similar to that previously reported in water at pH ∼7. These results, considered alongside our theoretical

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molecules | free full-text | free radical mediated oxidative

Molecules | Free Full-Text | Free Radical Mediated Oxidative

In the absence of antioxidants, carotenoids are unstable to heat, light and air/oxygen, degrading to compounds of smaller molecular weight. Following a report that β-carotene might act as an anticarcinogenic agent [ 11 ], several research groups began working to establish the effectiveness of these compounds as antitumor agents and also to

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chemical and molecular mechanisms of antioxidants

Chemical and molecular mechanisms of antioxidants

Using molecular oxygen, it generates both O 2 −• and nitric oxide that spontaneously form ONOO −. HOCl is a powerful oxidant which plays an important role in bactericidal function . However, excess HOCl is also highly reactive towards a range of biological substrates and may cause tissue injury.

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the antioxidant controversy – when should your patient be

THE ANTIOXIDANT CONTROVERSY – WHEN SHOULD YOUR PATIENT BE

Antioxidants that can react with molecular oxygen and are reducing agents are able to act as prooxidants. These antioxidants can generate superoxide radicals and dismutate to H 2 O 2 under aerobic conditions. This then reacts with reduced metal ions and superoxide to form toxic reactive oxygen species (ROS).

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rational design and biological application of antioxidant

Rational Design and Biological Application of Antioxidant

Introduction. Reactive oxygen species (ROS) are produced in the normal physiological activities of aerobic organisms. Oxygen (O 2) undergoes a series of electron transport in biological metabolism, which results in the formation of ROS, such as superoxide anion radical (O 2 •-), hydrogen peroxide (H 2 O 2), hydroxyl radicals (• OH) (Winterbourn, 2008; Dickinson and Chang, 2011; Nathan and

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free radical mechanisms in autoxidation processes | journal

Free radical mechanisms in autoxidation processes | Journal

Sulfinyl radical formation from the reaction of cysteine and glutathione thiyl radicals with molecular oxygen. Biochemical and Biophysical Research Communications 1987 , 144 (2) , 1037-1042.

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the mechanism of antioxidant action in vitro | springerlink

The Mechanism of Antioxidant Action in Vitro | SpringerLink

Abstract. The spontaneous reaction of atmospheric oxygen with organic compounds leads to a number of degradative changes that reduce the lifetime of many products of interest to the chemical industry, especially polymers, as well as causing the deterioration of lipids in foods.

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adsorption and activation of molecular oxygen over atomic

Adsorption and activation of molecular oxygen over atomic

Molecular O 2 is the simplest and most abundant oxidant for combustion, oxidation and electrochemical reactions. The O 2 activation pathway depends on the nature of the catalytic active site

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molecular hydrogen and aging – vital reaction

Molecular Hydrogen and Aging – Vital Reaction

H₂ is a molecular hydrogen antioxidant that also crosses the blood brain-barrier with ease, and accesses parts of the cell that other antioxidants are incapable of reaching. At Vital Reaction, our H₂ supplement is a natural antioxidant and anti-inflammatory molecule, which works rapidly to promote wellness and balance within the body

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ceutics test 3 chemical kinetics and stability part 1

Ceutics Test 3 Chemical Kinetics and Stability Part 1

Common degradation process for many organic molecules; This reaction of a drug with molecular oxygen is referred to as autooxiation spontaneous air oxidation _________ may be manifested as products with unpleasant odor, taste, appearance, discoloration, or even slight loss of activity

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