Sustainable lubricant compositions made from recycled thermoplastic polyesters and other reclaimed or biorenewable reactants and a method of formulating them are disclosed. The lubricant compositions comprise a polyester base oil, which incorporates recurring units from a digested thermoplastic polyester, a low-molecular-weight polyol, and C.sub.8-C.sub.24 fatty acid. The base oil has a number-average molecular weight within the range of 300 to 5000 g/mol, a hydroxyl value less than 50 mg KOH/g, and a viscosity at 40 C. less than 5000 cSt. Some of the lubricant compositions comprise the polyester base oil and one or more additives including anti-wear agents, corrosion inhibitors, antioxidants, thickeners, detergents, and the like. The lubricants have properties that rival those of commercial products made from nonrenewable hydrocarbon blends or polyol esters and are useful for many practical applications such as internal combustion engine oils, gear lubrication oils, hydraulic oils, compressor oils, metal working fluids, and lubricating greases.

Provided is a lubricating oil composition comprising a base oil (A) containing a polyalkylene glycol (A1) and a polyol ester (A2), a phosphorus-based rust inhibitor (B), and an antioxidant (C) containing an amine-based antioxidant (C1). The lubricating oil composition exhibits a strong effect for suppressing sludge sedimentation even when used for an extended period of time in a high-temperature environment, and has excellent demulsibility and rust preventive properties, and therefore, can be suitably used in turbomachinery, compressors, hydraulic equipment, and machine tools.

A lubricant composition including a binuclear molybdenum compound (A) and a trinuclear molybdenum compound (B), wherein these compounds are included in a range represented by (molybdenum of the binuclear molybdenum compound (A)):(molybdenum of the trinuclear molybdenum compound (B))=99.98:0.02 to 95:5 as a mass ratio.

The present disclosure relates generally to lubricating compositions and methods of making and using the same. Specifically, the present disclosure relates to lubricating compositions and method of making and using the same for modifying friction at a metal-elastomer contact, and therefore improving at least one of elastomer lifetime, reducing elastomer wear, reducing metal wear, reducing energy consumption or a combination thereof. More specifically, one aspect of the present disclosure relates to lubricating compositions including at least two base oils with a viscosity difference between the first and second base oils; another aspect of the present disclosure relates to lubricating compositions comprising an additive that can modify friction at a metal-elastomer contact.

Provided are; a lubricating oil composition excellent in fuel saving performance, seizure resistance, wear resistance, fatigue lifetime and shear stability, which contains a base oil (A), an olefin polymer (B) having a number average molecular weight of 1,000 or more and 12,000 or less, and a specific sulfur compound (C) and wherein the content of all sulfur atoms based on the total amount of the composition is 1.2% by mass or more and 2.5% by mass or less; and a lubrication method using the lubricating oil composition.

Disclosed are solvency enhancer compositions, for example, as additives to lubricating oils and as formulated in lubricating oil compositions and associated methods of preparation and use thereof. The compositions and methods can dissolve at least one of oxidation products and other organic polar compounds, due to lubricant degradation, formed and suspended in oil compositions including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols. Further described are methods for dissolving organic deposits in an oil system including adding an effective amount of a solvency enhancer to the oil system, wherein the solvency enhancer includes Guerbet alcohols. Also provided are methods for preventing sludge and varnish formation in in-service oils including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols.

Provided are compositions, additives for forming compositions, methods of operating apparatus in fluid communication with the compositions, and apparatus comprising the compositions. For example, the composition may include a polyalphaolefin component of from about 95% to about 99.5% w/w. The composition may include an additive component. The additive component may include an anti-wear agent. The anti-wear agent may be from about 0.1% to about 2% w/w. The anti-wear component may be characterized by an acid value of at least about 1 mg KOH/g. The additive component may include an aryl amine antioxidant agent, an anti-rust agent, and a metal deactivator agent. The composition may be characterized by a kinematic viscosity at 100 C. of at least about 5 centiStokes, a viscosity index of at least about 80, and an acid value in mg KOH/g of between about 0.1 and about 1.

Provided is a lubricating oil composition containing a base oil (A) and an amine-based antioxidant (B), wherein the component (B) contains a phenyl-naphthylamine (B1), an alkylphenyl-naphthylamine (B2) and a di(alkylphenyl)amine (B3), the content of the component (B1) is 2.0 to 10.0% by mass relative to 100% by mass of the total amount of the component (B), the content of the component (B2) is 40.0 to 90.0% by mass relative to 100% by mass of the total amount of the component (B), and the content of the component (B3) is 8.0 to 50.0% by mass relative to 100% by mass of the total amount of the component (B). The lubricating oil composition maintains excellent oxidation stability even in long-term use in high-temperature environments, and has an excellent lifetime and is excellent also in a sludge preventing effect.

Provided is a mineral base oil having a kinematic viscosity at 40 C. of 4.0 mm.sup.2/s or more and less than 6.0 mm.sup.2/s, a kinematic viscosity at 100 C. of 1.0 mm.sup.2/s or more and less than 2.0 mm.sup.2/s, and a flash point of 140 C. or higher. A lubricating oil composition containing the mineral base oil has a high flash point while having a low viscosity and thus having excellent fuel-saving performance when used as a driving system oil and the like.

A thermodynamic cycle such as an organic Rankine cycle system, utilizing a lubricant and a working fluid, for a machine in which pressurized gaseous working fluid is expanded to a lower pressure level and the energy from the fluid expansion is transformed into mechanical rotation energy; the lubricant includes a polyalkylene glycol based lubricant composition and the working fluid includes a mixture of alcohol and water.