A polyalkylene glycol-based compound may have formula (1):

##STR00001##

wherein R.sup.1 is a monovalent aromatic hydrocarbon group having 6 to 42 ring carbon atoms; R.sup.2 is a monovalent aromatic hydrocarbon group having 6 to 42 carbon atoms or a hydrogen atom; R.sup.3 is a divalent hydrocarbon group having 2 to 4 carbon atoms; and m is a number in a range of from 1 to 40.

A polyalkylene glycol-based compound may have formula (1):

##STR00001##

wherein R.sup.1 is a monovalent aromatic hydrocarbon group having 6 to 42 ring carbon atoms; R.sup.2 is a monovalent aromatic hydrocarbon group having 6 to 42 carbon atoms or a hydrogen atom; R.sup.3 is a divalent hydrocarbon group having 2 to 4 carbon atoms; and m is a number in a range of from 1 to 40.

A polyalkylene glycol having an end-group of the general formula: ##STR00001## in which each R.sup.2 independently represents a hydroxyl, alkyl, alkenyl, aryl, heteroaryl, benzyl, or polyalkylene glycol group, and each R.sup.3 independently represents a hydroxyl, alkyl, alkenyl, aryl, heteroaryl, benzyl, or polyalkylene glycol group; m is 0, 1, 2, 3, 4, 5 or 6; and n is 0, 1, 2 or 3. A lubricating oil composition comprising this polyalkylene glycol. A refrigerant composition comprising this polyalkylene glycol. A method of lubricating moving parts of an industrial or automotive system comprising applying a composition to the parts, wherein the composition comprises this polyalkylene glycol.

A polyalkylene glycol having an end-group of the general formula: ##STR00001## in which each R.sup.2 independently represents a hydroxyl, alkyl, alkenyl, aryl, heteroaryl, benzyl, or polyalkylene glycol group, and each R.sup.3 independently represents a hydroxyl, alkyl, alkenyl, aryl, heteroaryl, benzyl, or polyalkylene glycol group; m is 0, 1, 2, 3, 4, 5 or 6; and n is 0, 1, 2 or 3. A lubricating oil composition comprising this polyalkylene glycol. A refrigerant composition comprising this polyalkylene glycol. A method of lubricating moving parts of an industrial or automotive system comprising applying a composition to the parts, wherein the composition comprises this polyalkylene glycol.

An automotive lubricant base oil formulation contains a base oil, preferably a hydrocarbon base oil, having a kinematic viscosity of 100 centiStokes or less at 40 degrees Celsius and an ailcyl capped oil soluble polymer where the alkyl capped oil soluble polymer has the structure of Formula 0): where R.sup.1 is an alkyl having from one to thirty carbons, R.sup.2 and R.sup.3 are independently selected from alkyl groups having three or four carbons and can be in block form or randomly combined, R.sup.4 is an alkyl having from one to 18 carbon atoms, n and m are independently numbers ranging from zero to 20 provided that n+m is greater than zero and p is a number within a range of one to three and a kinematic viscosity of 100 centiStokes or less at 40 degrees Celsius is useful in a lubricant for mechanical devices.
R.sup.1[O(R.sup.2O).sub.n(R.sup.3O).sub.mR.sup.4].sub.p  (I)

An automotive lubricant base oil formulation contains a base oil, preferably a hydrocarbon base oil, having a kinematic viscosity of 100 centiStokes or less at 40 degrees Celsius and an ailcyl capped oil soluble polymer where the alkyl capped oil soluble polymer has the structure of Formula 0): where R.sup.1 is an alkyl having from one to thirty carbons, R.sup.2 and R.sup.3 are independently selected from alkyl groups having three or four carbons and can be in block form or randomly combined, R.sup.4 is an alkyl having from one to 18 carbon atoms, n and m are independently numbers ranging from zero to 20 provided that n+m is greater than zero and p is a number within a range of one to three and a kinematic viscosity of 100 centiStokes or less at 40 degrees Celsius is useful in a lubricant for mechanical devices.
R.sup.1[O(R.sup.2O).sub.n(R.sup.3O).sub.mR.sup.4].sub.p  (I)

Compositions, methods, systems, and applications herein are directed to lubricant blends that balance solubility and viscosity of a refrigerant, where in some cases the lubricant blends herein help reduce solubility of a refrigerant. A lubricant blend includes a mixture of two or more different types of lubricants to reduce refrigerant solubility.

Provided is a lubricating oil composition for a refrigerator which uses a base oil including as the main component at least one kind of oxygen-containing compounds selected from polyoxyalkylene glycols, polyvinyl ethers, copolymers of poly(oxy)alkylene glycols or monoethers thereof and polyvinyl ethers, polyol esters, and polycarbonates. The lubricating oil composition for a refrigerator is used for a refrigerator that uses, as a refrigerant, a fluorine-containing organic compound, which is a refrigerant applicable to current car air conditioner systems or the like and has a specific polar structure, and has favorable sealing property, a low coefficient of friction factor in a sliding part, and excellent stability as well as excellent compatibility with the refrigerant.

Provided is a lubricating oil composition for a refrigerator which uses a base oil including as the main component at least one kind of oxygen-containing compounds selected from polyoxyalkylene glycols, polyvinyl ethers, copolymers of poly(oxy)alkylene glycols or monoethers thereof and polyvinyl ethers, polyol esters, and polycarbonates. The lubricating oil composition for a refrigerator is used for a refrigerator that uses, as a refrigerant, a fluorine-containing organic compound, which is a refrigerant applicable to current car air conditioner systems or the like and has a specific polar structure, and has favorable sealing property, a low coefficient of friction factor in a sliding part, and excellent stability as well as excellent compatibility with the refrigerant.

A lubricant composition includes: an oil selected from among polyalkylene glycols (PAG); and a nitrogen compound selected from among amine phosphates or amine tungstates. The lubricant composition is particularly suitable for lubricating a vehicle engine, preferably a motor vehicle engine. Also disclosed is an engine lubrication method utilizing such composition.