Naphthenic oil

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... 

Plasticizers and Processing Aids. Petroleum-based oils are commonly used as plasticizers. Compound viscosity is reduced, and mixing, processing, and low temperature properties are improved. Air permeabihty is increased by adding extender oils. Plasticizers are selected for their compatibihty and low temperature properties. Butyl mbber has a solubihty parameter of ca 15.3 (f /cm ) [7.5 (cal/cm ) ], similar to paraffinic and naphthenic oils. Polybutenes, paraffin waxes, and low mol wt polyethylene can also be used as plasticizers (qv). Alkyl adipates and sebacates reduce the glass-transition temperature and improve low temperature properties. Process aids, eg, mineral mbber and Stmktol 40 ms, improve filler dispersion and cured adhesion to high unsaturated mbber substrates. 

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). 

FIGURE 16.12 Mooney viscosity at 175°C of butadiene elastomer mill mixed with 50 phr of N-234 10 phr of naphthenic oil with the labeled loading of a commercial peptizer (diphenyl dibenzamido-disulfide). 

Naphthenic oils give good processability and compatibihty in diene elastomers and the resulting vulcanizates are relatively nonstaining. 

A considerable amount of work has already been successfully carried out in HASETRI with naturally occurring oils as eco-friendly process oils in conventional tire recipes [31,32]. These naturally occurring oils were found to be suitable on the basis of low PCA content. Some of the naturally occurring oils showed better processing properties, polymer-filler interaction, and dispersion properties in NR-based truck tire tread cap compound and hence better mechanical and dynamic mechanical properties. As the presently available low PCA oil in the market in the form of MES TDAE and naphthenic oil are comparatively costly, these natural oils can act as the best alternative processing aids for the elastomer industry, especially in developing and underdeveloped countries. 

Aromatic oils are the most compatible with NR and give improved dispersion of fillers. If staining is a problem then a naphthenic oil with known low- or non-staining character should be used. 

Naphthenic oils are compatible with CR in levels of up to 15-20 phr. They disperse in the compound rapidly. Paraffinic oils, unless used below the 5 phr addition level, will tend to bloom. At 1-3 phr dosage however, they can be useful in improving processability of compounds containing them. 

The carcinogenicity of polycyclic aromatic compound-rich tyre extender oils has lead to the proposal of a legislative ban on their use in Europe. The suitability of naphthenic oils as non-toxic plasticisers in tyre treads is discussed and results are presented of experimental studies of the use of these plasticisers in SBR, EPDM, sulphur-cured EPDM and peroxide-cured EPDM. Despite their low aromatic content, the naphthenic plasticisers are shown to give good results in SBR, probably as a result of the contribution to solvent characteristics of the naphthenic molecular structure. The use of naphthenic oils is expected to increase worldwide as they are said to be one of the best alternatives to aromatic extracts with regard to solvent properties, compatibility, performance and availability. 

Another example would be the use of naphthenic oils in the formulation of compressor lubricants, textile processing oils, and other industrial lubricants. In these formulations, solubilizing and dispersing compounds within an oil is quite important. 

Fluidizer Oil Compounds such as polyisobutylene or refined naphthenic oils which aid in the removal of deposits from the underside of intake valves. 

Gelatinous Nitrate Containing Polyisobuty lene-Gelled Naphthene Base. Increased plasticity of dynamite-type expls is achieved by adding 1—10% of a gel based upon naphthene oil 95 and polyisoburylene 5 parts. Lubricating oil, heat-exchange oil or petrolatum. may be substituted for the naphthene Ref J.M. Downard, USP 2537039(1951) CA 45, 2670(1951)... 

Paraffinic oils may be more efficient than naphthenic oils by virtue of the shape of the... 

It is interesting that the amount of oil deposit required for 95% kill is approximately the same for eggs of the oriental fruit moth and of the citrus red mite. For eggs of the oriental fruit moth, Pearce et al. 21) report lowest minimum effective dosage values of 1.6 mg. per 100 sq. cm. for a paraffinic oil and 2.3 mg. per 100 sq. cm. for a naphthenic oil. Equivalent values for 95% kill of citrus red mite eggs in the present studies were 21 and 15 micrograms per sq. cm., respectively. 

Cadmium oxide Thiuram Naphthenic oils Barium sulfate Chromium oxide... 

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