A lubricating composition comprises at least 50 percent by mass, based on the mass of the composition of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of an oil-soluble poly(2-oxazine) polymer. The polymer has the repeat unit:

##STR00001##

where the number (n) of repeat units is an integer between 4 and 500, such as between 4 and 400. The polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. R.sup.1 comprises a single or a mixture of linear, branched or cyclic hydrocarbyl groups having 1-50 carbon atoms, some or all having 12-50 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms.

A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of an oil-soluble copolymer, The copolymer comprises units (a) and units (b):

N(COR.sup.1)CH.sub.2CH.sub.2(a)

N(COR.sup.2)CH.sub.2CH.sub.2CH.sub.2(b)

wherein the polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit (a) or (b), the initiator group (i) being effective to initiate the polymerisation of linear branched or cyclic hydrocarbyl moieties. R.sup.1 and R.sup.2 are the same or different and comprise a single or a mixture of linear, branched or cyclic hydrocarbyl groups having 1-50 carbon atoms, some or all having 12-50 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms.

Disclosed in certain embodiments is a lubricating grease composition comprising an antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula I

##STR00001##

wherein
R is H, C.sub.1-C.sub.18 alkyl, C.sub.2-C.sub.18 alkenyl, C.sub.2-C.sub.18 alkynyl, C(O)C.sub.1-C.sub.18 alkyl, C(O)aryl and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently H or a linear or branched C.sub.1-C.sub.18 alkyl, C.sub.1-C.sub.18 alkoxy, C.sub.1-C.sub.18 alkylamino, C.sub.1-C.sub.18 dialkylamino, C.sub.1-C.sub.18 alkylthio, C.sub.2-C.sub.18 alkenyl, C.sub.2-C.sub.18 alkynyl or C.sub.7-C.sub.21 aralkyl and
wherein
the number average molecular weight (Mn) of the polymer composition is from about 350 g/mol to about 5000 g/mol.

An antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula I

##STR00001##

wherein R is H, C.sub.1-C.sub.18 alkyl, C.sub.2-C.sub.18 alkenyl, C.sub.2-C.sub.18 alkynyl, C(O)C.sub.1-C.sub.18 alkyl, C(O)aryl and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently H or a linear or branched C.sub.1-C.sub.18 alkyl, C.sub.1-C.sub.18 alkoxy, C.sub.1-C.sub.18 alkylamino, C.sub.1-C.sub.18 dialkylamino, C.sub.1-C.sub.18 alkylthio, C.sub.2-C.sub.18 alkenyl, C.sub.2-C.sub.18 alkynyl or C.sub.7-C.sub.21 aralkyl and wherein the number average molecular weight (Mn) of the polymer is from about 350 g/mol to about 5000 g/mol are highly effective antioxidants in lubricant compositions. The polymer compositions may be prepared by a process comprising subjecting diarylamine monomers to dehydrocondensation conditions.

Disclosed in certain embodiments is a lubricating oil composition comprising an antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula I

##STR00001## wherein R is H, C.sub.1-C.sub.18 alkyl, C.sub.2-C.sub.18 alkenyl, C.sub.2-C.sub.18 alkynyl, C(O)C.sub.1-C.sub.18 alkyl, C(O)aryl and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently H or a linear or branched C.sub.1-C.sub.18 alkyl, C.sub.1-C.sub.18 alkoxy, C.sub.1-C.sub.18 alkylamino, C.sub.1-C.sub.18 dialkylamino, C.sub.1-C.sub.18 alkylthio, C.sub.2-C.sub.18 alkenyl, C.sub.2-C.sub.18 alkynyl or C.sub.7-C.sub.21 aralkyl and wherein the number average molecular weight (Mn) of the polymer composition is from about 350 g/mol to about 5000 g/mol.

Provided is a lubricating composition for inhibiting plugging including a base oil and any one selected from a fatty acid and an emulsifier, with the lubricating composition forming a single phase even when a carboxylic acid-based monomer is introduced with respect to the base oil. The lubricating composition suppresses plugging occurring in a process of preparing a copolymer derived from the carboxylic acid-based monomer. In addition, also provided is a method of inhibiting plugging using the lubricating composition for inhibiting plugging.

The application relates to compositions comprising di-fatty-alkyl or -alkenyl polyalkylamines of the general formula (I) or (II), to a process for their preparation which involves a cyanoethylation step and a hydrogenation step, and their use as demulsifiers for oil-in-water emulsions, corrosion inhibitor, fuel additive, anti-scaling agent, asphalt additive, enhanced oil recovery agent for oil-wells, cutting-oil additive, and anti-static agent. The product show good performance combined with a favourable viscosity profile.

##STR00001##

Relating to the field of lubricant, more particularly relates to lubricant for marine engine, notably for a two-stroke marine engine. More particularly, relates to a lubricant for a marine engine including at least one lubricant base oil and at least one fatty amine.

A lubricant composition includes a controlled release friction modifier (CRFM), a highly paraffinic base stock, a dispersant and a detergent. The CRFM includes an ionic tetrahedral borate compound including a cation and a tetrahedral borate anion, wherein the tetrahedral borate anion comprises a boron atom having two bidentate di-oxo ligands of C.sub.18 tartrimide. The lubricant composition can also include at least one of a Group V co-base stock, an inorganic friction modifier, a viscosity modifier, and a cleanliness booster.

A lubricant composition of an oil of lubricating viscosity, an ashless condensation reaction product of an olefin polymer, having a number average molecular weight of 2,000 to 70,000, comprising carboxylic acid or equivalent functionality grafted onto the polymer backbone, with a monoamine or a polyamine often having a single primary amino group; a succinimide dispersant; and an overbased metal detergent, in an amount such that the total base number of the lubricant composition is less than 6.5, exhibits good sludge prevention performance in a gasoline engine.