A composition for enhanced heat transfer fluid performance. The composition includes at least one base heat transfer fluid. The at least one base heat transfer fluid undergoes one or more phase changes in a heat transfer process. The heat transfer process includes a heated zone and/or a cooled zone. The one or more phase changes increase heat removal from the heated zone and/or increase heat rejection in the cooled zone, as compared to heat removal from a heated zone and/or heat rejection in a cooled zone of a heat transfer process having a base heat transfer fluid that does not undergo one or more phase changes. The base heat transfer fluids can exhibit liquid crystal behavior (e.g., heat transfer fluids having nematic, smectic or discotic liquid crystals). A method for conducting heat transfer in a heating and/or cooling system using the compositions comprising the base heat transfer fluids.

A method for improving friction and wear control, while maintaining or improving energy efficiency, in an engine or other mechanical component lubricated with a lubricating oil, by using as the lubricating oil a formulated oil. The formulated oil has a composition including at least one lubricating oil base stock. The at least one lubricating oil base stock includes one or more liquid crystals, wherein the one or more liquid crystals are represented by the formula:

A(R1).sub.n

wherein A is a mono-ring or a multi-ring aromatic group, R1 is the same or different and is a substituted or unsubstituted, hydrocarbon, alkoxy, or alkylthio group having from 2 to 24 carbon atoms, and n is a value from 1 to 12. The lubricating oil base stock has a kinematic viscosity of 2 cSt to 200 cSt at 40 C., as determined according to ASTM D445, and a kinematic viscosity of 1 cSt to 25 cSt at 100 C., as determined according to ASTM D445.

Provided is a lubricant base stock, a lubricating oil including the lubricant base stock and a method for improving viscosity temperature performance or viscosity index of an engine or other mechanical component lubricated with the lubricating oil. The lubricant base stock includes one or more liquid crystals represented by the formula:

R1-(A).sub.m-Y(B).sub.nR2

wherein R1 and R2 are the same or different and are a substituted or unsubstituted, alkyl or alkoxy group having from 0 to 24 carbon atoms; A and B are the same or different and are a cycloaliphatic group or aromatic group, provided at least one of A and B is an aromatic group; Y is a covalent bond, CH2-CH2-, CHCH, CC, OCOO, COO, CO, CSO, CSS, CS, O, S, SO, SO2-, CH2O, OCH2O, NO, ONO2, COOH, OH, or CN; and m and n are independently 0, 1, 2 or 3. The lubricant base stock has a kinematic viscosity of 2 cSt to 28 cSt at 40 C., and 1 cSt to 12 cSt at 100 C.

Provided is a lubricant base stock, a lubricating oil including the lubricant base stock and a method for improving viscosity temperature performance or viscosity index of an engine or other mechanical component lubricated with the lubricating oil. The lubricant base stock includes one or more liquid crystals represented by the formula:

R1-(A).sub.m-Y(B).sub.nR2

wherein R1 and R2 are the same or different and are a substituted or unsubstituted, alkyl or alkoxy group having from 0 to 24 carbon atoms; A and B are the same or different and are a cycloaliphatic group or aromatic group, provided at least one of A and B is an aromatic group; Y is a covalent bond, CH2-CH2-, CHCH, CC, OCOO, COO, CO, CSO, CSS, CS, O, S, SO, SO2-, CH2O, OCH2O, NO, ONO2, COOH, OH, or CN; and m and n are independently 0, 1, 2 or 3. The lubricant base stock has a kinematic viscosity of 2 cSt to 28 cSt at 40 C., and 1 cSt to 12 cSt at 100 C.

The present disclosure relates to lubricant compositions comprising a branched copolymer and methods for making such compositions. Lubricant compositions of the present disclosure comprise an oil and a copolymer and have a high temperature high shear (HTHS) viscosity of about 5 or less, shear stability index (30 cycles) of from about 2% to about 80%, a ratio of thickening efficiency to shear stability index (30 cycles) of from about 1:2 to about 1:30, a kinematic viscosity at 100? C. of from about 3 cSt to about 30 cSt, and a thickening efficiency of about 1 or more. In another class of embodiments, the present disclosure provides a lubricant composition comprising a first and a second copolymers wherein the first copolymer has an ethylene content higher than that of the second copolymer, and wherein at least one of the two copolymers is a long chain branched ethylene copolymer.

The present disclosure relates to lubricant compositions comprising a branched copolymer and methods for making such compositions. Lubricant compositions of the present disclosure comprise an oil and a copolymer and have a high temperature high shear (HTHS) viscosity of about 5 or less, shear stability index (30 cycles) of from about 2% to about 80%, a ratio of thickening efficiency to shear stability index (30 cycles) of from about 1:2 to about 1:30, a kinematic viscosity at 100? C. of from about 3 cSt to about 30 cSt, and a thickening efficiency of about 1 or more. In another class of embodiments, the present disclosure provides a lubricant composition comprising a first and a second copolymers wherein the first copolymer has an ethylene content higher than that of the second copolymer, and wherein at least one of the two copolymers is a long chain branched ethylene copolymer.

A lubricating oil composition is provided which comprises (a) greater than 50 wt. % of a base oil of lubricating viscosity; and (b) 0.1 to 40 wt. % of an overbased alkaline earth metal alkyl-substituted hydroxyaromatic carboxylate, wherein the alkyl substituent is a residue derived from an isomerized alpha-olefin having from 12 to 40 carbon atoms, and having a TBN, on an actives basis, of less than 600 mg KOH/g, as determined by ASTM D 2896; wherein the lubricating oil composition is a monograde lubricating oil composition meeting specifications for SAE J300 revised January 2015 requirements for a SAE 20, 30, 40, 50, or 60 monograde engine oil, and has a TBN of 5 to 200 mg KOH/g, as determined by ASTM D2896.

A lubricating oil composition is provided which comprises (a) greater than 50 wt. % of a base oil of lubricating viscosity; and (b) 0.1 to 40 wt. % of an overbased alkaline earth metal alkyl-substituted hydroxyaromatic carboxylate, wherein the alkyl substituent is a residue derived from an isomerized alpha-olefin having from 12 to 40 carbon atoms, and having a TBN, on an actives basis, of less than 600 mg KOH/g, as determined by ASTM D 2896; wherein the lubricating oil composition is a monograde lubricating oil composition meeting specifications for SAE J300 revised January 2015 requirements for a SAE 20, 30, 40, 50, or 60 monograde engine oil, and has a TBN of 5 to 200 mg KOH/g, as determined by ASTM D2896.

A grease composition includes a base oil and a thickener. The thickener contains a urea compound and a styrene-based polymer. A content of the styrene-based polymer is 2% by mass or more and 30% by mass or less as to a total amount of the urea compound and the styrene-based polymer. In the thickener, an average value of diameter of particles with a diameter of 0.2 ?m or more is 0.2 ?m or more and 1.0 ?m or less.

A grease composition includes a base oil and a thickener. The thickener contains a urea compound and a styrene-based polymer. A content of the styrene-based polymer is 2% by mass or more and 30% by mass or less as to a total amount of the urea compound and the styrene-based polymer. In the thickener, an average value of diameter of particles with a diameter of 0.2 ?m or more is 0.2 ?m or more and 1.0 ?m or less.