2.2.4- Trimethyl-l,2-dihydroquinoline

GLYCOLS - ETTTYLENE GLYCOLAND OLIGOTffiRS] (Vol 12) 6-Ethoxy-2,2,4-trimethyl-l,2-dihydroquinoline [91-53-2]... 

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]. 

N-Nitroso compounds occur in many operations in the rubber industry. Some nitrosamines (nitrosodiphenylamine, N-N-dinitrosopentamethylenetetramine, polymerized N-nitroso 2,2,4-trimethyl-l,2-dihydroquinoline and N-methyl-N-4-dinitroso aniline) are used as organic accelerators and antioxidants in the production of rubber and often the products are found to be contaminated with such compounds [19]. 

ETHOXYTRIETHYLENE GLYCOL see EFLOOO ETHOXYTRIGLYCOL see EFLOOO 6-ETHOXY-2,2,4-TRIMETHYL-l, 2-DIHYDROQUINOLINE see SAVOOO... 

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]. 

Reports dealing with the technical application of polymeric AO are concerned mostly with aromatic amines. Excellent results in the stabilization of SBR or NBR articles in engineering applications were obtained with Chemigum HR (86) [77]. Oligomeric 2,2,4-trimethyl-l,2-dihydroquinoline (100) has been used successfully for many years in stabilization of vulcanized rubbers. Both 86 and 100 are efficient AO. The imporance of the application of polymeric phenolic AO for the stabilization of packaging materials for foods may be exemplified [114] The absorption of Poly AO-79 (97) in the gastrointestinal tract was studied with relationship to the M of the AO ... 

From 2,2,4-Trimethyl-l,2-dihydroquinoline Hydrochlorides and Guanidine-l-carbonitrile... 

Condensation of aniline with aldehydes and ketones yields 2,2,4-trimethyl-l,2-dihydroquinoline, which polymerizes to give an oxidant employed in the processing of elastomers. 

Trimethyl-17/,3//,5//-pyrido[3,2,l-jy][3,l]benzoxazines were detected among the reaction products of 2,2,4-trimethyl-l,2-dihydroquinoline with formaldehyde and acetaldehyde by liquid chromatography-mass spectroscopy (LC-MS) investigations (79MI1). 

Alkylated diphenylamines (11) and derivatives of both dihydroquinoline (12) and polymerized 2,2,4-trimethyl-l,2-dihydroquinoline [26780-96-1] (13) develop less color than the />-phenylenediamines and are classified as senhstaining antioxidants. Derivatives of dihydro quinoline are used for the stabilization of animal feed and spices. 

When staining tendencies of the substituted paraphenylene diamines cannot be tolerated, semistaining amine antioxidants are used to provide some protection to the elastomers. The semistaining antioxidants include polymerized 2,2,4-trimethyl-l,2-dihydroquinolines (13) and substituted diphenylamines such as 4,4,-bis(0C,CC-dimethylbenzyl)diphenylamine (14). These compounds protect unsaturated elastomers against oxidation but provide no protection against ozone. 

Both 102 and 108 were confirmed as (macro)alkyl radical scavengers in an oxygen deficient environment. 102 traps 1-cyano-l-methylethyl used in excess [107]. The respective thermolabile JV-alkylate 110 (R = EtO, 20% yield) and a stable 8-alkylate 111 (R = EtO, 50% yield) are formed. 6-Ethoxy-8-alkoxy-2,2,4-trimethyl-l,2-dihydroquinoline 112 (R=EtO, R1 = 1-cyano-l-methylethyl) is formed as the main product from 108, probably by isomerization of the O-substituted hydroxylamine generated in the first stage from 108. 

Poly(2,2,4-trimethyl-l,2-dihydroquinoline), an oligomeric antioxidant for rubber, is a typical example for this ionization method. Figure 6.3 shows the FD mass spectrum of a poly-TMDQ sample. Molecular ions for "normal" oligomers (M = 173n) are observed, along with minor peaks due to impurities (with differing end-groups) from the synthesis. 

Flectol H. See 2,2,4-Trimethyl-l, 2-dihydroquinoline polymer Flectol ODP. See p,p -Dioctyldiphenylamine Flectol TMQ. See 2,2,4-Trimethyl-1,2-dihydroquinoline polymer Fleetquest 8800. See Anthraquinone Fleshing grease, sulfated sodium salt. See Sodium tallow sulfate Flexalloy. See Polyvinyl chloride Flexan 130. See Sodium polystyrene sulfonate Flexathene TP 1300-HC, Flexathene TP 4300-HR, Flexathene TP 4390-HU. See Propylene/ethylene copolymer Flexbond 20, Flexbond 25, Flexbond 28, Flexbond 28S. See Acrylic resin Flexbond 149, Flexbond 150, Flexbond 153, Flexbond 165. See Polyvinyl acetate Flexbond 274, Flexbond 277, Flexbond 289. See Acrylic resin... 

Polymerized rosin. See Rosin, polymerized Polymerized siloxane. See Silicone Polymerized 2,2,4-trimethyl-1,2-dihydroquinoline. See 2,2,4-Trimethyl-l, 2-dihydroquinoline polymer Polymethacrylamidopropyl trimonium chloride CAS 68039-13-4... 

Many compounds have been reported in the literature to be chemical antiozonants, and nearly all contain nitrogen. Compound classes include derivatives of 2,2,4-trimethyl-l, 2-dihydroquinoline, N-substituted ureas or thioureas, substituted pyrroles, and nickel or zinc dithiocarbamate salts. The most effective antiozonants, however, are derivatives of p-phenylenediamine (p-PDA). The commercial materials are grouped into three classes N,N -dialkyl-p-PDAs, Nalkyl-N -ary 1-p-PDAs, and NX-diary 1-p-PI) As. The NX-dialkyl-p-PDAs (where the alkyl group may be 1-methylheptyl, l-ethyl-3-methylpentyl, 1,4-dimethylpentyl, or cyclohexyl) are the most effective in terms of their reactivity to ozone. These derivatives increase the critical stress required for the initiation of crack growth, and they also reduce the rate of crack growth significantly. The sec-alkyl group is most active, for reasons that are not yet completely clear. The drawbacks of these derivatives are ... 

Med ENB Medium ethylidene norbornene TMQ Polymerised 2,2, 4-trimethyl-l, 2-dihydroquinoline DTPD N, N-diaryl-paraphenylene diamine FEF Fast extrusion furnace SRF Semi-reinforcing furnace MBT 2-Mercapto benzothiazole TMTDS Tetramethyl thiuram disulfide Tetrone A Dipentamethylene thiuram tetrasulfide ... 

Altenau and co-workers [26,27] used MS to identify quantitatively volatile antioxidants in 0.02-0.03 inch thick samples of synthetic styrene-butadiene rubbers and rubber-type vulcanisates. They extracted the polymer with acetone in a Soxhlet apparatus, removed excess solvent, and dissolved the residue in benzene. Substances identified and determined by this procedure include N-phenyl-P-napthylamine, 6-dodecyl-2,2,4-trimethyl-l,2-dihydroquinolines, trisnonylphenylphosphate, isobutylene-bisphenol, 2-mercaptobenzothiazole sulfenamide (accelerator), N-cyclohexyl-2-benzothiazole... 

Poly-2,2,4-trimethyl-l,2-dihydroquinoline or p-phenylenediamine type. N-Oxydiethylenebenzothiazole-2-sulphenamide. kcs = kilocycles to failure. 

Antioxidants with a nitrogen heterocycle (such as dihydropyridine or dihydroquinoUne derived compounds) are far less frequently used, because of their higher toxicity. An example of such an antioxidant issantokin (6-ethoxy-2,2,4-trimethyl-l,2-dihydroquinoline), which is used by the feed industry. The active form in fats is a free radical (11-23). The water-soluble analogue of a-tocopherol, 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid with the trade name trolox (11-24) has found use in biological, biochemical and food research. It is mainly used as a standard for measuring antioxidant capacities of other compounds. Many other antioxidants are used in cosmetics, the petrochemical industry and elsewhere. 

Ogawa and co-workers [62] carried out an analysis of the components obtained by Py-GC-MS at 350-650 °C of the components of ozone deteriorated rubber sheets containing quinoline type antioxidants such as polymerised 2,2,4-trimethyl-l,2-dihydroquinoline. There were three peaks related to the antioxidant in the pyrogram of each nitrile rubber sheet. An examination was made of the relationship between the decrease of the antioxidant and the mechanical strength of the sheet. It was found that the mechanical strength of the nitrile rubber sheet surface layer (0.1 mm) became zero when the content of this antioxidant reached 50% or less of its original level. 

An aq. soln. of 2,2,4-trimethyl-l,2-dihydroquinoline hydrochloride allowed to react with dicyanodiamide 2-guanidino-4-methylquinazoline. Y 68%. F. e. s. J. P. Brown, Ghem. Ind. i960, 233. 

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