Antioxidant aromatic amine

Stilbenequiaones such as (5) absorb visible light and cause some discoloration. However, upon oxidation phenolic antioxidants impart much less color than aromatic amine antioxidants and ate considered to be nondiscoloring and nonstaining. 

Aromatic Amines. Antioxidants derived from -phenylenediarnine and diphenylamine are highly effective peroxy radical scavengers. They are more effective than phenoHc antioxidants for the stabilization of easily oxidized organic materials, such as unsaturated elastomers. Because of their intense staining effect, derivatives of -phenylenediamine are used primarily for elastomers containing carbon black (qv). 

Antioxidants resistant to extraction by lubricants and gasoline are preferred for the stabili2ation of elastomers used in automotive appfications such as gaskets and tubing. Aromatic amine antioxidants, such as A/-phenyl-Ar-(p-toluenesulfonyl)-A-phenylenediamine [100-93-6] (37), with low solubifity in hydrocarbons, are extracted slowly from elastomers and are used for these appfications. 

Raw NBR containing 1.5% of the built-in antioxidant retained 92% of its original resistance to oxidation after exhaustive extraction with methanol. NBR containing a conventional aromatic amine antioxidant (octylated diphenyl amine) retained only 4% of its original oxidative stabiUty after similar extraction. 

It is also possible to graft an aromatic amine antioxidant bearing a sulfhydryl group on to the backbone of an elastomer. 

Fluorescence is much more widely used for analysis than phosphorescence. Yet, the use of fluorescent detectors is limited to the restricted set of additives with fluorescent properties. Fluorescence detection is highly recommended for food analysis (e.g. vitamins), bioscience applications, and environmental analysis. As to poly-mer/additive analysis fluorescence and phosphorescence analysis of UV absorbers, optical brighteners, phenolic and aromatic amine antioxidants are most recurrent [25] with an extensive listing for 29 UVAs and AOs in an organic solvent medium at r.t. and 77 K by Kirkbright et al. [149]. 

The thermal stability of elastomeric polyacetaldehyde could be improved by end-capping the hydroxyl end groups with acetic anhydride in order to prevent chain unzipping. Further stabilization was obtained by adding polyamide as a thermal stabilizer and an aromatic amine antioxidant. 

Aromatic amine antioxidants were prepared by condensation of aniline, aralkylated diphenylamine or 2,2,4-trimethyl-l,2-dihydroquinoline with formaldehyde [165]. The latter was also used for the synthesis of other stabilizers a LS was formed via condensation with 2,4-dihydroxybenzophenone [166], a MD 131 with 2-hydroxy 4-methoxyacetophenone [167], another MD was formed with 8-hydroxyquinoline [168] and a BIO-S 132 with 4-aminosalicylic acid [169]. 

Naugard 445 is non-discoloring aromatic amine antioxidant that works synergistically with phosphites and phenolic antioxidants as a thermal stabilizer in polyolefins, styrenics, polyols, hot melt adhesives, lubricants, and polyamides. 

An optimized blend of liquid phenolic antioxidant and liquid aromatic amine antioxidant with a small amount of a phosphite stabilizer. This blend was specifically developed for use as a heat and color stabilizer for polyols used for making flexible polyurethane foam. 

Use Aromatic amine antioxidant for synthetic lubricants, lubricating greases, and industrial oils. 

Naugalube . [Umroyal] Alkylated secondary aromatic amine antioxidant for automatic transmissitm fluids, turbine oils, synthetic jet turbine lubricants petroleum additives. 

The LD-MS of Compound 8, which contains the Wingstay 300 antiozonant and an aromatic antioxidant, has characteristic peaks at m/z 268, 211, and 183 representative of the antiozonant and new peaks present at m/z 352, 288, 274, and 260. These latter three peaks are thought to represent the three molecular ions of the components of the antioxidant mixture in Goodyear s Wingstay 100, an aromatic amine antioxidant. 

Figure 3.2 Separation of aromatic amine antioxidants using Zipax. Column 1000 mm x 2.1 mm id, packing 0.5% 3, 3"-oxydipropionitrile on 20-37 pm Zipax support, carrier gas iso-octane, flow rate 0.31 ml/min, sample 10.6 pi of a mixture of 9.5 pg/ml each of N,N-diethylaniline and N-ethylaniline, 29 pg/ml of diphenylamine and 52 pg/ml of N-phenyl-...

Polymeric aromatic amine antioxidant produced by a reaction between p-phenylenediamine and benzoquinone at room temperature. 

The use of phenolic and amino-based antioxidants (ie, thermal stabilizers) by this approach has been limited because they inhibit the free-radical polymerization process (polymerization inhibitor) leading to lower efficiency. One of the few commercial products produced is based on the polymerizable chain breaking antioxidant (AO 12b, Table 3), designed for NBR rubbers (Chemigum HR 665) that has been shown to offer superior antioxidant performance, especially imder aggressive (hot oil/high temperature) conditions, compared to low molecular mass conventional aromatic amine antioxidants (165). In spite of the successful synthesis and copoljmierization of a large number of reactive antioxidants, there is a lack of major commercial development and production of antioxidant systems... 

Aromatic amine antioxidants are also known as rubber antiaging agents they have the largest production quantity and are used mainly in rubber products. These antioxidants have low prices and remarkable antioxidant effects however, they could change the color of products, which limits their application in light colored and white goods. Significant aromatic amine antioxidants are diphenylamine, jo-phenylenediamine, quinoline, and their derivatives or polymers, and they can be used in natural rubber, styrene butadiene rubber (SBR), chloroprene rubber, and isoprene rubber. 

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