Alkylated phenylene diamines

Two types of stabilizers inhibit crack growth in rubbers microcrystalline waxes and alkylated phenylene diamines. A small quantity of the wax milled into a rubber will gradually diffuse to the surface where it will serve as a barrier impervious to ozone. A combination of wax and alkylated phenylene dicunine antiozonant is generally used for optimum protection. The exact function of antiozonant is still obscure but it is possible that it accelerates scission processes on the polymer surface producing a protective film of viscous products. 

Protection Against Flex Cracking. Most antioxidants including waxes provide oxidation protection under static conditions. However, most of them are not effective in mbber products subjected to dynamic flexing, eg, sidewall compounds in tires. The best dynamic protection is provided by either /V-alkyl-/V-phenyl or diaryl-/)-phenylene diamines. 

Peroxides N,N-Dimethyl-1,4-phenylenediamine (N,N-DPDD), N,N,N, N -tetra-methyl-l,4-phenylene-diamine (TPDD) Peroxides, e. g. alkyl hydroperoxides, oxidize N,N-DPDD to Wurster s red and TPDD to Wurster s blue. [17] [34]... 

Properties of Epoxy Resins Cured with Ring-Alkylated m-Phenylene Diamines... 

A systanatic investigation of isomeric phenylaie diamines and ring-alkylated MPD s as epoxy curing agents was performed. Initial studies on blends of phenylene diamine isoners shewed that 20% substitution of OPD in MPD increased the Tg of the cured resin but decreased the tensile strength and elongation. When used alone, OPD resulted in resins of inferior properties. 

Of course, this re-equilibration behavior of two homopoly(amic acids) can be eliminated if one of the components does not exhibit this back reaction. Recombination of different fragments is not possible and stable polyimide precursor blends are accessable [119]. For example, combining a relatively flexible poly(amic acid), hexafluoroisopropylidene diphthalic anhydride (6F)/2,2-bis(4-aminophenoxy-4 -phenyl) propane (BDAF), with a rigid poly(amic alkyl ester), PMDA/p-phenylene diamine (PDA), produced microphase separated polyimide blends as can be interred by the persistence of the... 

The peroxidase-catalyzed oxidation of 2,2 -azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), o-phenylene-diamine (PDA), and 3,3, 5,5 -tetramethylbenzidine (TMB) was found to be activated by tetrazole 2 and 5-aminote-trazole and weakly inhibited by 1,5-diaminotetrazole 33 <2004MI283>. Bhattacharya and Vemula studied the effect of heteroatom insertion in the side chain of 5-alkyl-177-tetrazoles on their properties as catalysts for ester hydrolysis at neutral pH <2005JOC9677>. l-(2-Iodophenyl)-177-tetrazole was successfully used in Heck reactions to give the cross-coupled products in excellent yield <2004TL4113>. 

Ammonium salts with two different alkyl chains were prepared directly via subsequent alkylations of dimethylamine with primary bromides and crystallization. Commercial hexadecyl-methylamine can be conveniently applied in the same way in order to convey functionality to cationic synkinons. A recent example describes subsequent alkylations with a small functional and a long-chain primary bromide (Scheme 2.4). A-acylated / -phenylenediamine was also alkylated at the second nitrogen atom which had two different alkyl chains, with or without extra functionality . After deacylation, this head group can be diazotized or coupled oxidatively with various heterocycles in water (Scheme 2.4). Photoactive and coloured membrane surfaces are thus obtained. Phenylene-diamine, pyridine and in particular A-methyl-4,4-bipyridinium chloride are relatively weak nucleophiles. Substitution of bromides is slow and the more reactive iodides can rarely be obtained commercially, but the selection of nitromethanes as solvent for bromide substitution is of great help as well as the addition of sodium iodide to enforce a Finkelstein reaction or a combination of both. 

The same oxygen synergy as with phenolic inhibitors is exhibited with diphenyl aromatic compounds and phenylene diamine compounds (ref. 15). However, phenothiazine is a rather different case. Indeed it is well known that phenothiazine directly reduces alkyl radicals and not peroxy radicals (ref. 16), and that it works better in anaerobic environments (ref. 17). 

The alkyl esters of N-benzimidazol-2-yl-carbamic acid (22) can be prepared by the methylation of thiourea with dimethyl sulfate and the subsequent N-acylation in alkaline medium of the S-methyl-isothiourea formed (23) with the alkyl ester of chloroformic acid. Finally, N,N -bis(alkoxycarbonyl)-S-methylthiourea (24), obtained as an intermediate product is condensed with o-phenylene diamine in glacial acetic acid. 

The product can be filtered off as a dark brown crystalline substance (Harvey, 19S9 Klopping, 1960 Littrell et al., 1967). They can also be synthesised by the reaction of calcium cyanamide with chloroformic acid alkyl ester and o-phenylene diamine (Adams and Schlatter, 1966 Toth et al., 1972 Burmakin et al., 1974), or by the reaction of alkyl cyano carbamates (25), produced by the treatment of cyanamide with chloroformic acid alkyl ester, with o-phenylene diamine (Adams and Schlatter, 1969), or by the reaction of cyanamide with alkyl mercaptan, chloroformic acid alkyl ester and o-phenylene diamine (Schlatter, 1970) ... 

The synthesis of substituted benzimidazolone analogues (Xi H) was started from appropriate 2-chloronitrobenzenes (VII) as outlined in Scheme 3. The reaction of VII with aminoalkanols in an inert solvent afforded N-hydroxy-alkyl-2-nitroanilines (VIII). Catalytic hydrogenation of the nitro group resulted in o-phenylene-diamines (IX) which reacted with urea to give the N-hydroxyalkyl-benzimidazol-2-ones (X). After treatment of Xwith thionylchlo-ride, the desired chloroalkylbenzimidazol-2-ones (I) could be isolated. 

The effect of ozone is both greatly delayed and reduced when various antiozonants, such as NJ -di-alkyl-p-phenylene-diamines (X) or similar compounds, are incorporated in the rubber. They may react directly with ozone or with the ozone-olefin reaction products in such a way as to prevent chain scission. SBR is much more receptive to protection than either the nitrile or natural rubbers. Of the latter two the nitrile is more readily inhibited. If a wax is also added in small quantities with the antiozonant, the retardation of the attack of ozone is in certain instances enhanced several fold. 

Synonyms N,N -Di-2-naphthalenyl-1,4-benzenediamine sym-Di-P-naph-thyl-p-phenylenediamine DNPD 2-Naphthyl-p-phenylene diamine Classification Alkylated p-phenylenediamine Empirtal CjsHaNi Formula C6H4(NHC,oH,)2... 

N,N -Di- 3-naphthyl-p-phenylene- diamine DNPD Alkylated phenol APH... 

Solvent extraction gas chromatographic methods have been described for determining alkylated cresols (2,6-di-tert-butyl-p-cresol) and amine antioxidants (N-phenyl-2-naphthylamine, p-phenylene diamine type) and Santoflex (NN sec-heptyl phenyl-p-phenylene diamine) in polybutadiene. 

The separation of gas mixtures by polymeric membranes has become a commercially important methodology for a number of different systems (1). Several recent review articles have discussed the interaction between polymer structure and gas permeability properties (2,3). The quantification of the effect of polymer structure on gas transport properties recently has been reported (4,5) and it is now possible to optimize gas transport properties for well defined polymeric materials. For those materials which do not have a well defined data base it is necessary to prepare and measure the gas transport properties. The polyamide-imides (PAI) are a class of polymeric materials which do not have an extensive data base for gas transport properties (6,7). Work by Yamazaki and coworkers (8) demonstrated that PAI materials could be prepared easily and in a manner whereby the amide bond could be prepared from a phosphite activated carboxylic acid and an aromatic amine. Yang and CO workers (9-11) have shown that novel dicarboxyl ic acids could be prepared from trimellitic acid anhydride (TMA) and aromatic diamines and that these dicarboxylic acids could be coupled with a second diamine to form regiospecific PAI materials. Our focus was to examine the effects of a phenylene diamine and its alkylated analogs on the gas transport properties of regiospecific PAI materials and to identify those structures which maximized both permeability and selectivity. 

PPD is the highest volume antiozonant used today by the rubber industry. Millions of pounds of this antiozonant are used annually. It is of the alkyl aryl p-phenylene diamine class of antiozonant. Because of its solubility characteristics in compounds... 

The hindered phenol antioxidants Formula 4.4 and aromatic amines (e.g., p-phenylene diamines, Formula 4.1) both operate by kinetic chain-breaking processes. They donate a hydrogen to an alkyl peroxide radical and break the free radical chain with reactions such as below. 

Another important characteristic of the monomers is the presence of pendant groups attached to the aromatic ring. These pendant groups include alkyl, halogen, alkoxy, cyano, acetyl, and nitro. In addition to the simple phenylene compounds, diamines and diacid chlorides based on naphthalene and 4,4 -biphenyl have been used. A variety of monomers with bridging units of the following form have also been explored ... 

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