Aromatic and heterocyclic amines in polymer stabilization

Pospı́šil, J.

doi:10.1007/bfb0025229

Cited by 97 publications

(20 citation statements)

References 170 publications

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“…Other mechanisms that have been reported examined the possibility that the diphenyl amine radical formed in the first step in Figure 14 could disproportionate and then react with itself to form more complex species that eventually lead to poly conjugated systems upon reaction with additional hydroperoxy radicals. The reaction of N-phenyl-1-naphthylamine proceeds somewhat differently due to the susceptibility of the α hydrogen of the naphthyl ring to radical attack leading to the formation of dimers and higher polymers as in Figure 15 [33] or the formation of quinone imines and naphthoquinones [34].…”

Section: Antioxidantsmentioning

confidence: 99%

Turbine Engine Lubricant and Additive Degradation Mechanisms

Johnson¹

2019

Aerospace Engineering

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Modern ester based synthetic lubricants have been used in various formulations with anti-oxidants, phosphorus based anti-wear additives and other additives for many years. The physical and chemical properties of both the basestock and additives are known to change through use. Basestocks are normally thought to degrade through various mechanisms, while additive can either degrade or are used as they react when they complete the function that they are added for. In this chapter, the composition of modern turbine engine lubricants and the mechanisms by which the lubricants degrade over time will be examined. Potential changes in bearing materials being evaluated for future engines and the effects of possible new ionic liquids based additives will be will be discussed as they relate to currently used additives. Also included will be a discussion of effects of degradation on the lubricant properties, how the changes affect turbine engines and how the changes can impact human health. These new materials introduce a number of new possible degradation schemes that must be evaluated before the materials enter widespread use.

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Section: Antioxidantsmentioning

confidence: 99%

Turbine Engine Lubricant and Additive Degradation Mechanisms

Johnson¹

2019

Aerospace Engineering

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“…For this reason, in some relevant literature, it is possible to find the abbreviation HATS (Hindered Amine Thermal Stabilizers) or HAS (Hindered Amine Stabilizers). A detailed overview of the various mechanisms proposed for HALS action can be found in [1].…”

Section: Hals-4 Hals-5mentioning

confidence: 99%

Hindered amine light stabilizers: introduction

Malík¹,

Ligner²

1998

Plastics Additives

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“…Aromatic amines are known to be sensitive to oxidative dehydrogenation which can lead to quinone type structures [23]. Moreover, the presence of the amido-nitrogen on the ring, providing increased electron density to the ring, should further increase the tendency of the amine to oxidize.…”

Section: Mechanism Of Interaction Of the Flame Retardants With Pu Foammentioning

confidence: 99%

Discoloration in Fire-Retardant Flexible Polyurethane Foams

Levchik¹,

Luda

Bracco

et al. 2005

Journal of Cellular Plastics

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The mechanism of discoloration (‘scorch’) of water-blown flame-retardant polyurethane (PU) foams has been studied. As UV spectroscopy showed, scorch is a kinetically controlled phenomenon, and it can occur either in flame-retardant or non-flame-retardant foams. Isolated isocyanate groups in the PU structure, which transform into aromatic amines, are mostly responsible for scorch. Some flame retardants tend to accelerate scorch, and it becomes visible during industrial foaming, especially in hot and humid weather conditions. UV, FTIR, 13C and 31P NMR and GC-MS study carried out with a model aromatic amine showed that aliphatic phosphate esters as well as aliphatic chloroalkyl phosphates tend to N-alkylate aromatic amines. N-alkylated aromatic amines are easier to oxidize to colored quinoid type chromophores compared to primary aromatic amines. Discoloration can be significantly decreased by using aromatic flame retardants or by applying proper antioxidants in combination with aliphatic flame retardants.

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Aromatic and heterocyclic amines in polymer stabilization

Cited by 97 publications

References 170 publications

Turbine Engine Lubricant and Additive Degradation Mechanisms

Turbine Engine Lubricant and Additive Degradation Mechanisms

Hindered amine light stabilizers: introduction

Discoloration in Fire-Retardant Flexible Polyurethane Foams

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