Aromatic oil

The hquid remaining after the solvent has been recovered is a heavy residual fuel called solvent-refined coal, containing less than 0.8 wt % sulfur and 0.1 wt % ash. It melts at ca 177°C and has a heating value of ca 37 MJ/kg (16,000 Btu/lb), regardless of the quaUty of the coal feedstock. The activity of the solvent is apparently more important than the action of gaseous hydrogen ia this type of uncatalyzed hydrogenation. Research has been directed to the use of petroleum-derived aromatic oils as start-up solvents (118). 

The petroleum oils are of three basic types aromatic, naphthemic, and paraffinic. Aromatic oils contain hazardous materials that require special handling precautions. Naphthenic oil does not contain hazardous levels of polynuclear aromatics (PNAs) and is less hysteretic. Because of these considerations the naphthenic oil is gaining in usage at the expense of more utilized aromatics. Paraffinic oil is only used modestly in tire compounds. The... 

Many attempts have been made to characterize the stabiUty of the colloidal state of asphalt at ordinary temperature on the basis of chemical analysis in generic groups. For example, a colloidal instabiUty index has been defined as the ratio of the sum of the amounts in asphaltenes and flocculants (saturated oils) to the sum of the amounts in peptizers (resins) and solvents (aromatic oils) (66) ... 

The most widely used plasticizers are paraffinic oils. Por appHcations that specify high use temperatures, or for peroxide cures, paraffinic oils of low volatihty are definitely recommended. However, since paraffinic oils exude at low temperatures from EPDM vulcanizates, or from high ethylene EPDMs, they are often blended with naphthenic oils. On the other hand, naphthenic oils interfere with peroxide cures. Aromatic oils reduce the mechanical properties of vulcanizates, and they also interfere with peroxide cures. Therefore, they are not recommended for EPM/EPDM. 

Plasticizers. These are used to improve compound processibiHty, modify vulcani2ate properties, and reduce cost. Por many appHcations, where cost and processibiHty are the objective, naphthenic and aromatic oils are preferred. They are inexpensive yet effective in improving processibiHty at high filler levels. The compatibiHty of the naphthenic oils is limited to about 20 parts per hundred mbber. Aromatic oils are more compatible and can be used at higher levels (132). 

Adhesives, Coatings, and Sealants. Eor these appHcations, styrenic block copolymers must be compounded with resins and oils (Table 10) to obtain the desired properties (56—58). Materials compatible with the elastomer segments soften the final product and give tack, whereas materials compatible with the polystyrene segments impart hardness. The latter are usually styrenic resins with relatively high softening points. Materials with low softening points are to be avoided, as are aromatic oils, since they plasticize the polystyrene domains and reduce the upper service temperature of the final products. 

Silicone Excellent resistance over unusually wide temperature range [—100 to 260°C (—150 to 500°F)] fair oil resistance poor resistance to aromatic oils, fuels, high-pressure steam, and abrasion... 

Comparison of Table 5.4 and 5.7 allows the prediction that aromatic oils will be plasticisers for natural rubber, that dibutyl phthalate will plasticise poly(methyl methacrylate), that tritolyl phosphate will plasticise nitrile rubbers, that dibenzyl ether will plasticise poly(vinylidene chloride) and that dimethyl phthalate will plasticise cellulose diacetate. These predictions are found to be correct. What is not predictable is that camphor should be an effective plasticiser for cellulose nitrate. It would seem that this crystalline material, which has to be dispersed into the polymer with the aid of liquids such as ethyl alcohol, is only compatible with the polymer because of some specific interaction between the carbonyl group present in the camphor with some group in the cellulose nitrate. 

Because of the in-chain ring the Tg is as high as -i-35°C and the polymer is therefore not rubbery at usual ambient temperatures. If, however, the polymer is blended with an aromatic oil or certain ester plasticisers a rubbery material is obtained. Because of the ability of the polymer to take up large quantities of oil the Tg of a polymer-oil blend can be as low as -60°C. Such polymer-oil blends can also incorporate very large amounts of filler. 

It is a very aromatic oil, useful in some bouquets, and is found naturally in storax and other balsamic substances. It is prepared by various methods, amongst them being the heating of cinnamic acid with lime to 200°. It is a colourless, highly refractive liquid having the following characters —... 

A PVC-poor light fraction separated from mixed plastic household waste was pyrolysed to yield aromatic oils and heat-providing gas. Target products were benzene, toluene, xylenes, and styrene. Problematic pollutants were... 

Source To, B.H., in Rubber Technology, Hanser Verlag, Munich, Germany, 2001. SBR 1500, 100 N-330, 50 Aromatic oil, 10 Zinc oxide, 4 Stearic acid, 2 6PPD, 2... 

SBR Cariflex S1215 BR Buna CB 10 Silica, Perkacil KS 408 Zinc oxide Stearic acid Aromatic oil Coupling agent, TESPT Santoflex 6PPD Wax PEG 4000 Perkacit TBBS Perkacit DPG Sulfur... 

Physical properties of carbon black-filled EPR and EPDM elastomers have been found to be comparable with the suUur-cured analogues [372]. Aromatic oils increase the optimum dose requirement for these compounds due to the reaction of the transient intermediates formed during radiolysis of the polymer with the oil as well as energy transfer which is particularly effective when the oil contains aromatic groups. The performance and oxidative stability of unfilled EPDM as well as its blend with PE [373], and the thermal stabdity and radiation-initiated oxidation of EPR compounds are reported by a number of workers [374,375]. 

Aromatic oils give the best processability but cause staining, color stabihty problems, and give vulcanizates with poor resistance to aging. 

Mostly, 75% of the extender oils are used in the tread, sub tread, and shoulder regions of a tire. About 10%-15% are used in the sidewall, 5% are used in the inner finer, and less than 10% are used in the remaining parts. A typical tire can contain up to 700 g of oil. All types of mineral oils should be handled and used with care, but special care is required in the handling of aromatic oils. High aromatic oils also referred to as distillate aromatic extracts (DAEs) or simply extracts have been traditionally used as extender oils for elastomeric applications [27]. Their popularity is explained by their good... 

Brack [81] has illustrated the analysis of antioxidants in a CB-free vulcanisate of unknown composition according to Scheme 2.7. Some components detected by off-line TD-GC-MS (cyclohexylamine, aniline and benzothiazole) were clearly indicative of the CBS accelerator other TD components were identified as the antioxidants BHT, 6PPD, Vulcanox BKF and the antiozonant Vulkazon AFS. In the methanol extract also the stabiliser ODPA was identified. The presence of an aromatic oil was clearly derived from the GC-MS spectra of the thermal and methanol extracts. The procedure is very similar to that of Scheme 2.3. 

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