Diphenylamine rubber antioxidants

Diphenylamine (8) reacts with nitrous acid to yield iV-nitrosodiphenylamine (180), formerly a useful rubber vulcanization inhibitor. As a toxic nitroso compound, its use is now restricted. The reaction between 8 and acetone yields A-phenylbenzeneamine, a rubber antioxidant. 3-Methyl-phenyl-1-benzenesulfonyltriazene (181) and its toluene analog, both made from the reaction between the diazonium salt of aniline and the corresponding sulfonamide, have been used as blowing agents for rubber. 

Diaminodiphenylamine p,p -Diaminodiphenylamine Di(p-aminophenyljamine Diazol Black C Diphenylamine, 4,4-diamino- EINECS 208-673-4 4,4-lminodianiline Indamine NSC 33417 p-Phenylenediamine, N-(p-aminophenyl)-. A proprietary trade name for a rubber antioxidant. Also used to dye fur and to detect hydrogen cyanide. Leaflets mp = 158° bp dec very soluble in EtOH, Et20. 

Isobutylene reacts with ammonia to make f-butylamine, an important feedstock in the synthesis of TBBS rubber accelerator, one of the two most widely used accelerators. Isobutylene is dimerized to make diisobutylene, which is used to produce octy-lated diphenylamine (a commonly used rubber antioxidant) and para-t-octyl phenol (a feedstock for the most common phenolic tackifier resin used by the rubber industry). 

NBR antioxidant pLASTOTffiRS, SYNTTiETIC - NITRILE RUBBER] (Vol 8) Octylated diphenylamines [101-67-7]... 

Because nitrile rubber is an unsaturated copolymer it is sensitive to oxidative attack and addition of an antioxidant is necessary. The most common practice is to add an emulsion or dispersion of antioxidant or stabilizer to the latex before coagulation. This is sometimes done batchwise to the latex in the blend tank, and sometimes is added continuously to the latex as it is pumped toward further processing. PhenoHc, amine, and organic phosphite materials are used. Examples are di-Z fZ-butylcatechol, octylated diphenylamine, and tris(nonylphenyl) phosphite [26523-78-4]. All are meant to protect the product from oxidation during drying at elevated temperature and during storage until final use. Most mbber processors add additional antioxidant to their compounds when the NBR is mixed with fillers and curatives in order to extend the life of the final mbber part. 

In an acetone extract from a neoprene/SBR hose compound, Lattimer et al. [92] distinguished dioctylph-thalate (m/z 390), di(r-octyl)diphenylamine (m/z 393), 1,3,5-tris(3,5-di-f-butyl-4-hydroxybenzyl)-isocyanurate m/z 783), hydrocarbon oil and a paraffin wax (numerous molecular ions in the m/z range of 200-500) by means of FD-MS. Since cross-linked rubbers are insoluble, more complex extraction procedures must be carried out (Chapter 2). The method of Dinsmore and Smith [257], or a modification thereof, is normally used. Mass spectrometry (and other analytical techniques) is then used to characterise the various rubber fractions. The mass-spectral identification of numerous antioxidants (hindered phenols and aromatic amines, e.g. phenyl-/ -naphthyl-amine, 6-dodecyl-2,2,4-trimethyl-l,2-dihydroquinoline, butylated bisphenol-A, HPPD, poly-TMDQ, di-(t-octyl)diphenylamine) in rubber extracts by means of direct probe EI-MS with programmed heating, has been reported [252]. The main problem reported consisted of the numerous ions arising from hydrocarbon oil in the recipe. In older work, mass spectrometry has been used to qualitatively identify volatile AOs in sheet samples of SBR and rubber-type vulcanisates after extraction of the polymer with acetone [51,246]. 

Over half of the remaining market for products used in the processing of rubber is made up of antioxidants, antiozonants and stabilizers, either amino compounds or phenols. Aniline is used to manufacture vulcanization accelerators, antioxidants and antidegradants. Of the latter, several are A-substituted derivatives of p-phenylenediamine and octyl dipheny-lamine. Diphenylamines terminate free-radical reactions by donating the amino hydrogen, and are used to protect a wide range of polymers and elastomers. Many synthetic rubbers incorporate alkylated diphenylamine antioxidants. Other antioxidants include aryl amine resinous products from, e.g. condensation of aniline and acetone in the presence of... 

The 9,9-dimethylacridan formed in the reaction between diphenylamine and acetone, besides functioning as an antioxidant, also improves the flex life of rubber vulcanizates since it forms a more stable nitroxji radical than the alkylated diphenylamines. 

Uses Intermediate for paints rubber accelerators and antioxidants dyes and pigments intermediates photographic chems. isocyanates for urethane foams pharmaceutical intermediate explosives petrol, refining phenolics diphenylamine herbicides fungicides epoxy curing agents... 

Thiols add to diene rubbers by a free-radical mechanism. Thus antioxidants, like 4-(mercapto-acetamido)-diphenylamine, add -SH groups to the double bonds of cis-polyisoprene and polybutadiene in the presence of free>radical initiators. " ... 

Dicumyl diphenylamine Synonyms 4,4 -Bis (a,a -dimethylbenzyl) diphenylamine p-DicumyIdiphenylamine Diphenylamine, a-methylstyrenated Classification Alkylated diphenylamine Empirical C30H31N Properties Powd. m.w. 405.59 Uses Antioxidant in rubber and lubricants Trade Name Synonyms Dusantox 86 [Sovereign http //www.sovereignchemical.com], Oxoflex DPA Pastille [Sovereign http //www.sovereignchemical.com]... 

Dioctyloxostannane. See Dioctyltin oxide Dioctylperoxydicarbonate. See Di (2-ethylhexyl) peroxydicarbonate 4,4 -Dioctylphenylamine. See p,p -Dioctyldiphenylamine 4,4 -Di-t-octylphenylamine Synonyms Diphenylamine, octylated Octylated diphenylamine ODPA Empirical C28H43N Properties M.w. 393.66 Uses Antioxidant for plastics, rubber, and lubricants... 

Synonyms Diphenylamine, styrenated SDPA Empirical C28H27N Properties Liq. m.w. 377.54 Uses Antioxidant for natural and syn. rubbers, latex, polyesters, polyamides, polyolefins, POM, PU, lubricants, food-grade polymers/adhesives/rubbers for inner tubes sponge rubber seals/gaskets soles latex goods... 

Trimethyl-1,2-dihydroquinoline polymer antioxidant, light metal soldering flux Hydrazine sulfate antioxidant, light-colored rubber N,N -Di-o-tolylethylenediamine antioxidant, linear saturated polyesters N,N -Hexamethylene bis (3,5-di-t-butyl-4-hydroxyhydrocinnamamide) antioxidant, liposomes Phosphatidylcholine antioxidant, liver health maintainance Thioctic acid antioxidant, lube oils Anthranilic acid antioxidant, lubricant Methylcyclohexanol antioxidant, lubricant additives 4,4 -Bis (a,a-dimethylbenzyl) diphenylamine antioxidant, lubricants... 

BHT Bisphenol A, polybutylated Diphenylamine-acetone Distearyl thiodipropionate Nickel dibutyidithiocarbamate Zinc diisobutyidithiocarbamate Zinc 2-mercaptotoluimidazole antioxidant, SR rubber food-contact Cyclohexyl-N -phenyl-p-phenylenediamine antioxidant, stabilized polymers Perchloropentacyclodecane antioxidant, staining carpet backcoating latex foams... 

Figure 3.2 shows high speed chromatograms obtained with mixtures of N,N-diethylaniline, N-ethylaniline, diphenylamine and N-phenyl-2-naphthylamine amine antioxidants used in rubber manufacture. 

Elastomers. Polyunsaturated elastomers are sensitive to oxidation. Stabilizers are added to the elastomers prior to vulcanization to protect the rubber during drying and storage. Nonstaining antioxidants such as buty-lated hydroxytoluene (1), 2,4-bis(octylthiomethyl)-6-methylphenol [110553-27-0], 4,4 -bis(a, a -dimethylbenzyl)diphenylamine (14), or aphosphite such as tris(nonyl-phenyl)phosphite (24) may be used in concentrations ranging from 0.01 to 0.5%. 

The principal classes of primary antioxidants for rubber remain the pheno-lics (nonblack articles) and amines (black-filled articles). Among the amine t5q>es are the substituted diphenylamines,para-phenylenediamines (PPD, (10), where R,R = alkyl or aryl), and polymeric trimethyl-dihydroquinoline (TMQ). Representative phenolic antioxidants are given in Table 14, and selected amine antidegradants are given in Table 15. The majority of tire and mechanical goods made from general-purpose rubbers are protected by the phenolic and amine antioxidants. 

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. 

A new class of antioxidants obtained from the condensation reaction of dia-rylamines and formaldehyde was reported by scientists at B.E Goodrich in U.S. Patent 1,890,916 issued on December 13,1932, for the stabilization of rubber. In one example, four moles of diphenylamine was reacted with 0.5 moles of formaldehyde to yield tetra phenyl methylene diamine with a melting point of 103-106°C. This class of antioxidant was effectively used by scientists at ICI for improving the resistance of polyethylene to oxidation. 

Aniline hydrochloride is directly used to produce diphenylamine, a very important feedstock in the production of 6PPD antiozonant, octylated diphenylamine antioxidant, and ADPA AO, all produced for rubber use. 

Diisobutylene reacts with diphenylamine to produce octylated diphenylamine antioxidant for rubber. 

Diphenylamine reacts with acetone to produce acetone diphenylamine condensation product antioxidant for rubber. 

Antioxidants.. Antioxidants are obtained by reactions involving formaldehyde and amines. According to Semon , tetraphenyhnethylenediamine, produced refluxing a mixture of 36 per cent formaldehyde with an excess of diphenylamine in benzene solution, acts a a good antioxidant when employed to the extent of 0.1 to 5 per cent in a rubber composition. An antioxidant is also obtained by the reaction of diphenylamine, formalde-hyde, and cyclohesanoP ... 

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