Synthetic fluids

The main synthetic fluids used as special lubricants are esters, polyglycols, silicones, halogenated hydrocarbons and polyphenyl ethers. 

Demulsibility of petroleum oils and synthetic fluids NFT 60-125 ISO 6614 ASTM D 1401 Time necessary for separation of phases... 

Synthetic fluids are safe, noncorrosive, essentially nontoxic, and thermally stable when operated under conditions recommended by the manufacturers. Generally, these fluids are more expensive than petroleum oils, but the synthetics can usually be reprocessed to remove degradation products. There are several classes of chemicals offered permitting a wide temperature range of appHcation. Any heat-transfer fluid in use should be examined periodically to monitor degradation or contamination. 

The manufacturers of synthetic fluids offer technical service and consultation, and fluid reprocessing service can be arranged between the suppHer and the user. Complete physical properties and detailed information concerning synthetic fluids are reported in the manufacturers product Hterature (13—36). The physical characteristics of the synthetic fluids can be found in Table 1. 

Alkylated aromatic lubricants, phosphate esters, polyglycols, chlorotrifluoroethylene, siUcones, and siUcates are among other synthetics that came into production during much that same period (28,29). Polyphenyl ethers and perfluoroalkyl polyethers have followed as fluids with distinctive high temperature stabiUty. Although a range of these synthetic fluids find appHcations which employ their unique individual characteristics, total production of synthetics represent only on the order of 2% of the lubricant market. Poly(a-olefin)s, esters, polyglycols, and polybutenes represent the types of primary commercial interest. 

Properties provided by the branched hydrocarbon chain stmcture of these PAO fluids include high viscosity index in the 130—150 range, pour points of —50 to —60° C for ISO 32 to 68 viscosity range (SAE lOW and SAE 20W, respectively), and high temperature stabifity superior to commercial petroleum products. In their use in automotive oils such as Mobil 1, some ester synthetic fluid is normally included in the formulation to provide sufficient solubihty for the approximately 20% additives now employed in many automotive oils. 

The formation of nitrosamines, e.g. n-nitrosodiedianolamine, which are possible human carcinogens, can occur in synthetic or semi-synthetic fluids which contain a nitrite salt and diethanolamine or triethanolamine. 

Avoid the use of water-mix synthetic fluids containing nitrites if there is a technologically effective alternative. 

In a fully synthetic FR fluid, the fire resistance is due to the chemical nature of the fluid in the others, it is afforded by the presence of water. The other main distinction between the two groups is that the fully synthetic fluids are generally better lubricants and are available for use at operating temperatures up to 150°C (272°F), but are less likely to be compatible with the conventional sealing materials and paints than are water-based products. 

Use soluble oils or synthetic fluids at their recommended dilutions only, and avoid skin contact with their concentrates . ... 

Synthetic-based muds are mineral oil muds in which the oil phase has been replaced with a synthetic fluid, such as ether, ester, PAO, or linear alkylbenzene, and are available from major mud companies. The mud selection process is based on the mud s technical performance, environmental impact, and financial impact. Synthetic muds are expensive. Two factors influence the direct cost unit or per-barrel cost and mud losses. Synthetic muds are the technical equivalent of oil-based muds when drilling intermediate hole sections. They are technically superior to all water-based systems when drilling reactive shales in directional wells. However, with efficient solids-control equipment, optimized drilling, and good housekeeping practices, the cost of the synthetic mud can be brought to a level comparable with oil-based mud [1308]. 

Synthetic fire-resistant fluids have been developed to replace petroleum-based fluids for many applications. Although there are several types of these less hazardous fluids, the only synthetic fluids discussed in this profile are phosphate esters and polyalphaolefins. The phosphate esters are tertiary esters of orthophosphoric acid, 0=P(0H)3, and may be triaryl, trialkyl, and alkyl/aryl. The polyalphaolefins are usually based on 2-decene and contain a mixture of oligomers (dimers, trimers, etc.). 

The massive contamination of NDE1A in alkaline synthetic fluids (3%) found by Fan et al Q) cannot be explained by known nitrosation kinetics of di- or triethanolamine. Instead, more powerful nitrosation routes, possibly involving nitrogen oxide (N0X) derivatives (e.g., N02> N O t) may be responsible for the amounts of NDE1A in these products (34). In fact, a nitrite-free commercial concentrate was shown to accumulate NDE1A up to about 10 0 days at which time the levels dropped dramatically (19). Inhibition of N0X contaminants may be an effective route to the inhibition of nitrosamine formation in metalworking fluids. 

Water Separability of Petroleum Oils and Synthetic Fluids... 

Epidemiological studies relevant to the evaluation of di- and triethanolamine and jV-nitrosodiethanolamine involve occupational cohorts exposed to metalworking fluids. Metalworking fluids can be divided into four broad categories straight oils, soluble oils, semi-synthetic and synthetic fluids. 

Semi-synthetic fluids contain smaller amounts of oil than soluble oils (3-30%), along with the same mixture of additives mentioned below for synthetic fluids. They are typically diluted 1 10 to 1 40 for use. This category has not been examined separately in epidemiological studies. One study (Sitllivan et al., 1998) grouped semisynthetic oil exposure with soluble oil exposures. 

Two cohort studies, two proportionate mortality studies and two nested case-control studies looked at cancer mortality or incidence among workers using metalworking fluids with ethanolamines as additives, with or without sodium nitrite. Small excesses were observed for cancers at various sites, in particular, stomach, oesophagus and larynx. In most of these studies, only associations with use of soluble oils or synthetic fluids were presented and no results were given specifically in relation to triethanolamine exposure. It is difficult to draw conclusions regarding triethanolamine using data from studies of exposures to these complex mixtures. 

Friedheim, J.E. and Conn, H.L. (1996) Second generation synthetic fluids in the... 

Norman, M Ross, S., McEwen, G. and GetlifF, J. (2002) Minimizing environmental impacts and maximizing hole stability - the significance of drilling with synthetic fluids in New Zealand. New Zealand Petroleum Conference Proceedings 24—27 February 2002. 

Other Synthetic Fluids. Other synthetic fluids are used as heat-transfer fluids although most of them are not sold specifically for this purpose. Fluids that sometimes are used include diethylene glycol, triethylene glycol, propylene glycol, butyl carbitol, w -cymene, several silanes, several silicone fluids, some silicate fluids, other polyalkylene glycols, other oiganic ethers, and other molten salts. Fluidized solids also are used as heat-transfer media. 

Synthetic fluid mediums, for use in in vitro studies, have been developed to simulate certain properties of vaginal and cervical fluids [20,34], and their compositions are detailed in Table 21.3 and Table 21.4, respectively. 

Semisynthetic oils are a combination of synthetic fluids and mineral oils. In these oils there is some reduction in friction, increase in film strength, and they oxidize at the same rate as a mineral oil product. These marginal benefits are realized at a higher cost than that of mineral engine oils. If you are going to synthetics, go all the way to full synthetics and gain all the benefits (Miller, 1993). 

Some applications of the synthetic fluids are motor oil, trucks, marine diesel, transmissions and industrial lubricants, aviation and aerospace lubricants, fire-resistant fluids, and greases. Specifications for several military lubricants can be met only by a synthetic product. All commercial and military jet aircraft engines use synthetic lubricants, in addition to the space shuttle, NASA, and nuclear submarines. 

Synthetic oils By using Table 2.7, Performance of synthetic and mineral lubricant oils , consider the benefits of using synthetic engine oils in several main aspects of (a) engine wear protection, (b) improved fuel and oil economy and (c) environmental protection. Which of the synthetic oils phosphate esters or alkylated aromatics (PAO) are the most common synthetic fluids used in automotive motor oils today ... 

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