Hydraulic fluids lubricating properties

Properties Colorless to light-yellow liquid. D 0.99 (25C), refr index 1.5560-1.5590 (25C), distilling range 152-158C (11 mm Hg). Partially soluble in water soluble in organic solvents. Combustible. Use Intermediate, oil-soluble rust inhibitor, cutting oils, hydraulic fluids, lubricants. 

PCBs are extremely stable to heat, chemical, and biological decomposition. They are excellent insulating and cooling fluids, extensively used for many years in manufacture of transformers and capacitors. PCBs are also used in hydraulic fluids, lubricating oils, paints, adhesive resins, inks, fire retardants, wax extenders, and numerous other products. The chemical and physical properties of PCBs make the remediation of polluted sites difficult. They resist degradation and absorb into soils and colloidal materials in water. Some persist with half-lives of 8-15 years in the environmental compartments. This stability contributes to their dispersion in the environment and long-range air pollution. Because they are lipophilic, these species are stored in fatty tissues and accumulate in the food webs (see Section 2.2). 

Chem. Descrip. Tolyltriazole (40%) in diethylene glycol Uses Corrosion inhibitor tor aq. and hydrocarbon systems, hydraulic fluids, lubricants, metalworking fluids, inks, compressor fluids, flooring, di-reot oopper treatments, transmission fluids, and paints Properties Deep yei. to amber clear sol n. flash pt. 290 F Cobratec TT-50-S [PMC Spec.]... 

The use of a series of vegetable oils including canola oil as base fluids for industrial and automotive applications has been discussed in the Uterature (Erhan and Perez, 2002). These vegetable oil-based products were prepared by chemical modifications of the epoxidized vegetable oils to produce environmentally friendly hydraulic fluids, lubricants, metalworking fluids and diesel engine oils. Environmentally friendly, nontoxic and biodegradable motor oil based on canola (Johnson et al., 2002) has shown superior properties compared with synthetic and conventional motor oils. 

Uses Emulsifier and coupling agent for paraffinic, naphthenic and organic ester lubricants, textiles, metalworking and hydraulic fluids, polymerization Properties Pale yel. oily liq. sol. in toluene, min. spirits, many veg. oils, acetone. 

Uses Skin softener, nonoily emollient for cosmetic creams/lotions, bath oils, blushers, skin fresheners, aftershaves, nail enamel removers binder lubricant dispersant emulsifier food-pkg. adhesives, coatings, paper, polymers defoamer for aq. systems, food contact, mold release applies., paints, ceramics, grinding fluids, hydraulic fluids lubricant base for textiles, paper, metalworking formulations chemical intermediate for fatty acid esters component for urethanes Regulatory FDA 21CFR 173.310,173.340(a)(3), 175.105,175.300,175.380, 175.390,176.170(a)(5), 176.180,176.200,176.210,177.1680,178.3740 Properties APHA40 max. liq., polyol odor sol. 5% in min. oils, min. spirits, aromatic soivs., perchloroethylene insol. in water m.w. 2000 sp.gr. 1.002 vise. 150-175 cst (100 F) vapor pressure < 0.1 mm Hg b.p. > 300 F acid no. 1 max. pour pt. -31 C flash pt. (PMCC) > 350 F ref index 1.450 100% act. 

The silicone oils and silicone resins find application as (i) lubricants (their change of viscosity with temperature is small), (ii) hydraulic fluids (they are unusually compressible), (iii) dielectric fluids, (iv) for the pro duction of water-repellant surfaces, and (v) in the electrical industry (because of their high insulating properties). 

Hydraulic Fluids and Lubricants. The use of borate esters in hydrauHc fluids (qv) and lubricants (see Lubrication and lubricants) has been described in numerous patents (40,43,44). A variety of borate esters have been described that can be used as multiflinctional lubricant additives having antiwear and antifriction properties (45). 

Fluoroelastomer (Vitou, Fluorel 2141, Kel-F) 450 Can be used at high temperatures with many fuels, lubricants, hydraulic fluids, solvents, highly resistant to ozone, weathering. Good mechanical properties. 

Both the dipolymers and terpolymers have excellent resistance to hydrocarbons found m petroleum-based fuels and lubricants The 69 5% F terpolymer resists swellmg m blended fuels that contain metlianol and can be used in contact with certain phosphate ester-based hydraulic fluids Terpolymers are preferred for contact with aromatic solvents, although either type performs well in higher alcohols VDF-based elastomers dissolve m polar aprotic solvents such as ketones, esters, amides, and certam ethers These elastomers are therefore not suitable for contact with fluids that contain substantial amounts of these solvents because of excessive swell and consequent loss of mechanical properties... 

With the trend toward higher pressures in hydraulic systems, the loads on unbalanced pump and motor components become greater and this, coupled with the need for closer fits to contain the higher pressures, can introduce acute lubrication problems. Pumps, one of the main centers of wear, can be made smaller if they can run at higher speeds or higher pressures, but this is only possible with adequate lubrication. For this reason, a fluid with good lubrication properties is used so that hydraulics is now almost synonymous with oil hydraulics in general industrial applications. Mineral oils are inexpensive and readily obtainable while their viscosity can be matched to a particular job. 

The five largest uses for PCBs prior to 1970 were dielectric fluids in capacitors, plasticizers, lubricants, transformer fluids, and hydraulic fluids. They were also used widely in protective coatings, sealers, putty, grinding fluids, printing inks, pattern waxes, carbonless paper, etc. (see Chap. 1). Because of this widespread PCB use they are found throughout the environment [363-365]. A number of important properties of PCBs are discussed below along with information on their distribution and persistence in the environment. 

PCBs are synthetic chemicals that exist as oils or waxy substances they do not occur naturally. They were once used in many products including hydraulic fluids, pigments, inks, plasticizers, lubricants, and heat transfer fluids, but their primary use was as a dielectric fluid in electrical equipment. Because of their high thermal stability, chemical stability, and electrical insulating properties, PCB fluids were used extensively in transformers, fluorescent light... 

The extent of the cross-linking and the nature of the alkyl or aryl substituent determines the nature of the polymers. They range from oily liquids to rubbery solids. All are water-repellant, thermally and electrically insulating and chemically inert. These properties render them widely useful in industry they appear as lubricants, antifoams, low temperature hydraulic fluids, and in cosmetics. 

Phosphate esters have been produced commercially since the 1920s and now have important applications as plasticisers, lubricant additives and synthetic-based fluids for hydraulic and compressor oils. Their first use in lubrication was as anti-wear additives. Later developments in aircraft hydraulic control systems, particularly during the Second World War, introduced phosphate esters as less flammable hydraulic fluids. As esters of orthophosphoric acid they have the general formula OP(OR)3, where R represents an aryl or an alkyl group or, very often, a mixture of alkyl and/or aryl components. The physical and chemical properties of phosphate esters can be varied considerably depending on the choice of substituents [59, 60], selected to give optimum performance for a given application. Phosphate esters are particularly used in applications that benefit from their excellent fire-resistant properties, but compared to other base fluids they are fairly expensive. 

Over the years, detergents have found equally important usage in many other types of lubricants, including gear oils, farm tractor hydraulic fluids, automatic transmission fluids and industrial oils. The performance properties that detergents impart to these lubricating fluids include rust and corrosion prevention, improvement in lubricant elastomeric seal compatibility, enhancement of sludge control under oxidative conditions and improvement of wet clutch and wet brake friction level and stability. 

Emulsions are in the HFAE and HFB groups of hydraulic fluids. The HFAE oil-in-water emulsions are more important, having a high water content, with very low flammability and are widely used due to their low cost. However, oil-in-water lubricants have a reduced wear protection compared with pure oils and, in addition, rust/corrosion and bacterial attack give problems. Improvement in these properties is achieved by using mst/corrosion inhibitors, bactericides and, if necessary, anti-wear additives. Suitable emulsifiers ensure good stability of the emulsions. 

Super tractor universal oils (STUOs), widely used in Europe and some other areas, are the extreme of multi-purpose lubricants. They arise from tractor hydraulic oils used for various hydraulic applications of agricultural machinery with added lubricant properties. STUOs have considerable advantages in reducing the number of oils required on a farm and reduce the possibility of wrong fluids in wrong reservoirs or machinery. Bulk purchases of one oil reduce unit costs against the costs of purchasing multiple hydraulic oils and lubricants. 

These properties allow them to be employed in a myriad of applications in addition to surface coatings, including plastic moldings (16). electrical insulators (17). cleaning substances, shoe-, furniture-, automotive, and floor waxes (18). in virological practice (19). cloth coatings, and mold release agents, biomedical applications, and hydraulic fluids and lubricants (20). 

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