The Hindered Phenols

Stillson, Gordon H.

doi:10.1021/ja01208a512

Cited by 6 publications

(8 citation statements)

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“…The integral intensity from the water peak was less than 5% of the integral intensity of signals of residual protons of DMSO d 6 . IR spectra were obtained on a Perkin-Elmer 1725 X spectrometer in KBr pellets (resolution 2 cm -1 ).…”

Section: Methodsmentioning

confidence: 85%

“…The fre quency region of 1475-1300 cm -1 usually remains uninterpreted; however, it contains bands for the most part of quinolide compounds and methylene quinones. The 1 H NMR spectra of potassium and sodium 2,6 di tert butylphenoxides in DMSO d 6 show that signals from the meta and para protons lie at δ 6.58 and 5.58, respec tively, which corresponds to the region of olefinic pro tons. Compared to the spectrum of the initial 2,6 di tert butylphenol, these signals exhibit noticeable upfield shift.…”

Section: Resultsmentioning

confidence: 99%

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Potassium and sodium 2,6-di-tert-butylphenoxides and their properties

Володькин

Заиков

2006

Russ Chem Bull

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The crucial factor of the reaction of 2,6 di tert butylphenol with alkali hydroxides is temperature, depending on which two types of potassium or sodium 2,6 di tert butylphenoxides are formed. These types exhibit different catalytic activity in the alkylation of 2,6 di tert butylphenol with methyl acrylate. More active forms of 2,6 Bu t 2 C 6 H 3 OK or 2,6 Bu t 2 C 6 H 3 ONa are synthesized at temperatures higher than 160 °C and are predominantly the monomers, which dimerize on cooling. The data of 1 H NMR, electronic, and IR spectra for the corre sponding forms of 2,6 Bu t 2 C 6 H 3 OK and 2,6 Bu t 2 C 6 H 3 ONa isolated in the individual state are in agreement with cyclohexadienone structure. In DMSO or DMF, the dimeric forms of 2,6 di tert butylphenoxides react with methyl acrylate to form methyl 3 (4 hydroxy 3,5 di tert butylphenyl)propionate in 64-92% yield.

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Section: Methodsmentioning

confidence: 85%

Section: Resultsmentioning

confidence: 99%

Potassium and sodium 2,6-di-tert-butylphenoxides and their properties

Володькин

Заиков

2006

Russ Chem Bull

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“…The latter are, however, soluble in the so-called Claisen solution (350 g potassium hydroxide in 250 g water made up to 1 L with methanol). In contrast to these partially sterically hindered alkylphenols, phenols with two bulky alkyl groups (e.g., tert-butyl, tertpentyl) in the ortho and one alkyl group in the para position are also insoluble in the Claisen solution [24]. Examples of such sterically hindered (shielded) phenols are 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-pentyl-4-methylphenol, and 2,4,6-tri-tert-butylphenol.…”

Section: Chemical Propertiesmentioning

confidence: 99%

“…The hydroxyl group can generally be esterified successfully with acid anhydrides or acid chlorides. In the case of sterically hindered phenols, conditions have to be modified as with etherification [24]. With the exception of 2,6-di-tert-alkylphenols the hydroxyl groups of the alkylphenols react with isocyanates to form urethanes, which can be used for identification of the alkylphenols [28].…”

Section: Chemical Propertiesmentioning

confidence: 99%

Phenol Derivatives

Fiege

Voges²,

Hamamoto

et al. 2000

Ullmann's Encyclopedia of Industrial Chemistry

188

175

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The article contains sections titled: 1. Alkylphenols 1.1. Physical Properties 1.2. Chemical Properties 1.3. Occurrence, Formation, Isolation 1.4. Production, General 1.4.1. Alkylation of Phenols 1.4.2. Other General Processes 1.5. Industrially Important Alkylphenols 1.5.1. Polymethylphenols 1.5.2. Ethylphenols 1.5.3. Isopropylphenols 1.5.4. sec ‐Butylphenols 1.5.5. tert ‐Butylphenols 1.5.6. tert ‐Pentylphenols 1.5.7. Higher Alkylphenols 1.5.8. Cycloalkylphenols 1.5.9. Aralkylphenols 1.5.10. Alkenylphenols 1.5.11. Indanols 2. Catechol 2.1. Physical Properties 2.2. Chemical Properties 2.3. Production 2.4. Uses 2.5. Economic Aspects 2.6. Toxicology 3. Trihydroxybenzenes 3.1. Pyrogallol 3.2. Hydroxyhydroquinone 3.3. Phloroglucinol 4. Bisphenols (Bishydroxyarylalkanes) 4.1. Physical Properties 4.2. Chemical Properties 4.3. Production 4.4. Analysis, Testing, Storage 4.5. Uses, Economic Aspects 4.6. Toxicology 5. Hydroxybiphenyls 5.1. Physical Properties 5.2. Chemical Properties 5.3. Production 5.4. Analysis, Quality Specifications, Storage 5.5. Uses 5.6. Toxicology 6. Phenol Ethers 6.1. Properties 6.2. Production 6.3. Representative Phenol Ethers 7. Halogen Derivatives of Phenolic Compounds 7.1. Introduction 7.2. Representative Compounds

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“…The most common antioxidants used in polyolefin are hindered phenol molecules, including octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate (Irganox® 1076) and pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate) (Irganox® 1010) [6,7] as illustrated in Scheme 2. However, there are several concerns of small organic HP molecules in the PP matrix, which often limit their effectiveness and the product's long-term performance.…”

Section: Introductionmentioning

confidence: 99%

Developing Polypropylene Bonded Hindered Phenol Antioxidants for Expanding Polypropylene Applications in High Temperature Conditions

Zhang¹,

C²,

Tc³

2017

J Material Sci Eng

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Polypropylene (PP) represents about a quarter of commercial plastics produced around the world. Despite its huge commercial success, PP polymer is not suitable for the applications that require long-term exposure to high temperatures (>80°C), due to its chemical and physical stability. The PP chain is prone to the oxidative chaindegradation and exhibits a relatively low material softening temperature. This paper discusses a new research approach by developing the PP-bonded hindered phenol (PP-HP) antioxidants to address this scientifically challenging issue. We have investigated two PP-HP structures, one with two methylene units adjacent to the hindered phenol group (HP-L) and one without this spacer (HP-S). In general, PP-HP polymers are advantaged with the ability to incorporate a suitable concentration of HP antioxidant groups with homogeneous distribution along the polymer chain, which provide effective protection to the PP chains from oxidative degradation. In addition, the specific PP-HP-L structure can also engage in a facile crosslinking reaction to form a 3-D network during the oxidation reaction. In one accelerated oxidation test in air at 190-210°C, the regular commercial PP polymer (containing common antioxidants and stabilizers) degrades within a few minutes; a PP-HP-L copolymer with about 1 mol% HP-L group shows almost no detectable weight loss after 24 hrs. In an ASTM endurance test at 140°C in air, the commercial PP shows 1% weight loss within about 10 days. On the other hand, the PP-HP-L polymer lasts for more than 30 years. Overall, the experiment results present the potential of expanding PP applications into a much higher temperature range (>140°C) under oxygen oxidative environments.

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The Hindered Phenols

Cited by 6 publications

References 0 publications

Potassium and sodium 2,6-di-tert-butylphenoxides and their properties

Potassium and sodium 2,6-di-tert-butylphenoxides and their properties

Phenol Derivatives

Developing Polypropylene Bonded Hindered Phenol Antioxidants for Expanding Polypropylene Applications in High Temperature Conditions

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