Modified styrene-maleic anhydride co-polymer composition and their use as lubricant additives

Abstract

The present disclosure relates generally to modified styrene-maleic anhydride copolymers and lubricants containing them. In various embodiments the disclosure provides a polymer composition that is a reaction product of components comprising: 35-60 parts by weight of a styrene / maleic anhydride copolymer, wherein the styrene / maleic anhydride copolymer comprises: 40-80 wt% styrene residues, and 20-60 wt% maleic anhydride residues, each based on a total weight of the styrene / maleic anhydride copolymer, at least 80 wt% of the styrene / maleic anhydride copolymer being formed of residues of styrene and maleic anhydride; 30-60 parts by weight of a C8-C24 hydrocarbyl primary amine component; and 0.5-5 parts by weight of a polyethyleneimine oligomer component, wherein a total amount of styrene residues, maleic anhydride residues, C8-C24 hydrocarbyl primary amine residues and polyethyleneimine oligomer residues is at least 80 wt% of the polymer composition.

Description

MODIFIED STYRENE-MALEIC ANHYDRIDE CO-POLYMER COMPOSITION AND THEIR USE AS LUBRICANT ADDITIVESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of priority of European Patent Application no. 24221154.8, filed December 18, 2024, which is hereby incorporated herein by reference in its entirety.BACKGROUND OF THE DISCLOSURE1 _ Field

[0002] The present disclosure relates generally to modified styrene-maleic anhydride copolymers and lubricants containing them.2. _ Technical Background

[0003] Lubricants generally comprise a base oil of a lubricating viscosity together with one or more additives to deliver various properties, including, e.g., reduced friction and wear, improved viscosity index, improved dispersancy, detergency, and resistance to oxidation and corrosion. A lubricant may comprise one or more base oils.

[0004] Base oils may be classified as Group I, II, III, IV, and V base stocks as set forth in API standard 1509, Annex E. Group I base stocks are typically manufactured by known processes including, for example, solvent extraction and solvent dewaxing, or solvent extraction and catalytic dewaxing. Group II and Group III base stocks are typically manufactured by known processes including, for example, catalytic hydrogenation and / or catalytic hydrocracking, and catalytic hydroisomerization. Group IV base stocks include for example, hydrogenated oligomers of alpha olefins.

[0005] Manufacturers aim to improve the fuel economy of modern internal combustion engines. Since the use of lubricants with low viscosity profiles can lead to improved fuel economy, modern engines are increasingly reliant on Ultra-Low Viscosity Engine Oils, which includes OW-16 grade engine oils and below. A lubricant formulation is required to have a sufficiently low kinematic viscosity at 20 °C (KV20), kinematic viscosity at 40 °C (KV40), and kinematic viscosity at 100 °C (KV100) in order to be classified as an Ultra-Low Viscosity Engine Oils. This presents a challenge to engine oil formulators. Conventional additives that impart various properties to a lubricant as described above can increase the viscosity of the lubricant formulation. As such, the addition of expensive Group IV base stocks with low viscosities are generally required for a lubricant formulation to meet the ultra-low viscosity requirements.

[0006] Accordingly, there is a need for additives that allow for lubricant formulations with rheological properties sufficient to be categorized as ultra-low viscosity engine oil. There is also a need for lubricant formulations that exhibit such viscosity profiles without necessitating the addition of a Group IV base oil.SUMMARY

[0007] In one aspect, the present disclosure provides a modified styrene-maleic anhydride co-polymer polymer composition as a lubricant additive. The polymer composition is a reaction product of components including:35-60 parts by weight of a styrene / maleic anhydride copolymer, wherein the styrene / maleic anhydride copolymer comprises:40-80 wt% styrene residues, and20-60 wt% maleic anhydride residues, each based on a total weight of the styrene / maleic anhydride copolymer, at least 80 wt% of the total weight of the styrene / maleic anhydride copolymer being formed of styrene and maleic anhydride residues;30-60 parts by weight of a C8-C24 hydrocarbyl primary amine component; and 0.5-5 parts by weight of a polyethyleneimine oligomer component, wherein a total amount of styrene / maleic anhydride copolymer residue, C8-C24 hydrocarbyl primary amine residues and polyethyleneimine oligomer residues is at least 80 wt% of the polymer composition.

[0008] In another aspect, the present disclosure provides a lubricant including: a base oil, and a polymer composition as described herein, present in an amount in the range of 0.1- 5 wt% of a total weight of the lubricant, as determined on a solids basis.DETAILED DESCRIPTION

[0009] Polymer Compositions

[0010] In one aspect, the present disclosure provides a modified styrene-maleic anhydride co-polymer polymer composition that is a reaction product of components comprising 35-60 parts by weight of a styrene / maleic anhydride copolymer, wherein the styrene / maleic anhydride copolymer comprises 40-80 wt% styrene residues and 20-60 wt% maleic anhydride residues, each based on a total weight of the styrene / maleic anhydride copolymer, at least 80 wt% of the styrene / maleic anhydride copolymer being formed of residues of styrene and maleic anhydride; 30-60 parts by weight of a C8-C24hydrocarbyl primary amine component; and 0.5-5 parts by weight of a polyethyleneimine oligomer component, wherein a total amount of styrene / maleic anhydride copolymer residue, C8-C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues is at least 80 wt% of the polymer composition.

[0011] As described above, the polymer compositions described herein are reaction products from reacting various nitrogen-containing compounds with a styrene / maleic anhydride copolymer. The styrene / maleic anhydride copolymer comprises styrene and maleic anhydride residues. As used herein, the term “residue” is understood to refer to a mono- or polyvalent radical resulting from the incorporation of a component into a polymerPh composition. For example, a “styrene residue” refers to the structureanc|a“maleic anhydride residue” refer to the structure(i.e., an unreacted form) or(i.e., a reacted form) For example, “a C8-C24 hydrocarbyl primary amineR i R i residue” refers to structures RNH2(unreacted material),(singly reacted)(doubly reacted), in which R is C8-C24 hydrocarbyl. Primary amine residues with hydrocarbyl groups of other sizes or descriptions are similarly defined. A “polyethyleneimine oligomer residue” analogously refers to a polyethyleneimine oligomer in the state in which it appears in the polymer composition (typically some mixture of degrees of reaction). The relative amounts of various residues can be quantified by the relative masses of these reactants -- the unreacted styrene, maleic anhydride, primary amine and polyethyleneimine components -- that are nominally necessary to arrive at the polymer composition, as a fraction of the mass of the polymer composition.

[0012] As noted above, in various aspects of the disclosure, the styrene / maleic anhydride copolymer includes 40-80 wt% styrene residues, based on a total weight of the styrene / maleic anhydride copolymer. For example, in various embodiments of the present disclosure as described herein, the styrene / maleic anhydride copolymer comprises styrene residues in the range of 40-75 wt%, e.g., in the range of 40-70 wt%, or in the range of 40-65 wt%, or in the range of 40-60 wt%, or in the range of 40-55 wt%, based on the total weight of the styrene / maleic anhydride copolymer. In various embodiments, the styrene / maleic anhydride copolymer comprises styrene residues in the range of 45-80 wt%, e.g., in the range of 45-75 wt%, or in the range of 45-65 wt%, or in the range of 45-60 wt%, or in the range of 45-55 wt%, based on the total weight of the styrene / maleic anhydride copolymer. In some embodiments, the styrene / maleic anhydride copolymer comprises styrene residuesin the range of 50-80 wt% styrene residues, e.g., in the range of 50-75 wt%, or in the range of 50-70 wt%, or in the range of 50-65 wt%, or in the range of 50-60 wt%, based on the total weight of the styrene / maleic anhydride copolymer. For example, in some embodiments, the styrene / maleic anhydride copolymer comprises styrene residues in the range of 55-75 wt%, or in the range of 55-70 wt%, or in the range of 55-65 wt%, based on the total weight of the styrene / maleic anhydride copolymer.

[0013] As noted above, in various aspects of the disclosure, the styrene / maleic anhydride copolymer includes 20-60 wt% maleic anhydride residues, based on a total weight of the styrene / maleic anhydride copolymer. For example, in various embodiments of the present disclosure as described herein, the styrene / maleic anhydride copolymer comprises maleic anhydride residues in the range of 25-60 wt%, e.g., in the range of 30-60 wt%, or in the range of 35-60 wt%, or in the range of 40-60 wt%, or in the range of 45-60 wt%, based on the total weight of the styrene / maleic anhydride copolymer. In various embodiments, the styrene / maleic anhydride copolymer comprises maleic anhydride residues in the range of 20-55 wt%, e.g., in the range of 25-55 wt%, or 30-55 wt%, or in the range of 35-55 wt%, or in the range of 40-55 wt%, or in the range of 45-55 wt%, based on the total weight of the styrene / maleic anhydride copolymer. In some embodiments, the styrene / maleic anhydride copolymer comprises maleic anhydride residues in the range of 20-50 wt%, e.g., in the range of 25-50 wt%, or 30-50 wt%, or in the range of 35-50 wt%, or in the range of 40-50 wt%, based on the total weight of the styrene / maleic anhydride copolymer. For example, in some embodiments, the styrene / maleic anhydride copolymer comprises maleic anhydride residues in the range of 20-45 wt%, e.g., in the range of 25-45 wt%, or 30-45 wt%, or in the range of 35-45 wt%, based on the total weight of the styrene / maleic anhydride copolymer.

[0014] While the person of ordinary skill in the art will appreciate that styrene / maleic anhydride copolymers can further include additional components such as residues from other ethylenically unsaturated monomers, the styrene / maleic anhydride copolymers described herein are substantially formed from styrene and maleic anhydride residues, with at least 80 wt% of the styrene / maleic anhydride copolymer being formed of residues of styrene and maleic anhydride. For example, in various embodiments as described herein, at least 90 wt%, e.g., at least 95 wt%, of the total weight of the styrene / maleic anhydride copolymer is formed of styrene and maleic anhydride residues. For example, in some embodiments, at least 98 wt%, e.g., at least 99 wt%, of the total weight of the styrene / maleic anhydride copolymer is formed of styrene and maleic anhydride residues.

[0015] The present inventors have found that the polymer compositions described herein have advantageous dispersing properties in lubricants while minimizing undesirable increases to the overall kinematic viscosity of the lubricant. Based on the presentdisclosure, the person of ordinary skill in the art can select a styrene / maleic anhydride copolymer having a weight-average molecular weight that provides the resulting polymer composition with desirable degrees of both of these properties. For example, in various embodiments as described herein, the styrene / maleic anhydride copolymer has a weightaverage molecular weight in the range of 2,000 to 20,000 g / mol, e.g., in the range of 2,000 to 15,000 g / mol, or in the range of 2,000 to 10,000 g / mol, or in the range of 2,000 to 7,000 g / mol, or in the range of 4,000 to 20,000 g / mol, or in the range of 4,000 to 15,000 g / mol, or in the range of 4,000 to 10,000 g / mol, or in the range of 4,000 to 7,000 g / mol. In some embodiments, the styrene / maleic anhydride copolymer has a weight-average molecular weight in the range of 3,000 to 7,000 g / mol, e.g., in the range of 3,500 to 7,000 g / mol, or in the range of 4,000 to 7,000 g / mol, or in the range of 4,500 to 7,000 g / mol. The weightaverage molecular weight of the styrene / maleic anhydride copolymer can be determined by performing gel permeation chromatography (GPC) on Agilent PLgel columns using tetra hydrofuran (THF) as the mobile phase and narrow molecular weight polystyrene as standards.

[0016] As described above, the polymer compositions described herein are reaction products of components including a C8-C24 hydrocarbyl primary amine, a polyethyleneimine oligomer, and a styrene / maleic anhydride copolymer. In various aspects, the reaction components comprise 35-60 parts by weight of the styrene / maleic anhydride copolymer, together with 30-60 parts by weight of the hydrocarbyl primary amine component and 0.5-5 parts by weight of the polyethyleneimine oligomer component. In various embodiments of the present disclosure as described herein, the polymer composition is a reaction product of components comprising in the range of 40-60 parts by weight of the styrene / maleic anhydride copolymer, e.g., in the range of 45-60 parts by weight, or in the range of 50-60 parts by weight, or in the range of 55-60 parts by weight. For example, in various embodiments, the polymer composition is a reaction product of components comprising in the range of 35-55 parts by weight of the styrene / maleic anhydride copolymer, e.g., in the range of 40-55 parts by weight, or in the range of 45-55 parts by weight, or in the range of 50-55 parts by weight. In some embodiments, the polymer composition is a reaction product of components comprising in the range of 35-50 parts by weight of the styrene / maleic anhydride copolymer, e.g., in the range of 40-50 parts by weight, or in the range of 45-50 parts by weight. For example, in some embodiments, the polymer composition is a reaction product of components comprising in the range of 35-45 parts by weight of the styrene / maleic anhydride copolymer, e.g., in the range of 35-40 parts by weight, or in the range of 40-45 parts by weight.

[0017] Styrene / maleic anhydride copolymers are generally insoluble in nonpolar media, such as the base oils typically used in lubricants. However, the present inventors have found that by condensing a C8-C24 hydrocarbyl primary amine onto the maleic anhydride residues of the styrene / maleic anhydride copolymer, the resulting polymer composition can be rendered more dispersible in nonpolar media. As used herein, the term “hydrocarbyl” refers to an acyclic substituent radical consisting of hydrogen and carbon atoms, wherein the substituent can be saturated or unsaturated, and linear or branched. Furthermore, the person of ordinary skill in the art can appreciate that primary amines can only have one substituent. Accordingly, a “C8-C24 hydrocarbyl primary amine” is understood to refer to an amino group (i.e., -NH2) with one C8-C24hydrocarbyl substituent. These can react with maleic anhydride or maleic acid residues to form, for example, amides and maleimides. Of course, in any reaction system there will typically be some degree of unreacted primary amine; the unreacted primary amine is quantified as part of the polymer composition if it remains together with the reacted polymer.

[0018] In various embodiments as described herein, the C8-C24hydrocarbyl primary amine component is a primary C8-C24alkyl amine, or a primary C8-C24alkenyl amine, or a combination thereof. As used herein, the term “alkyl” is used to refer to linear or branched hydrocarbyl substituents that are completely saturated (i.e., having no multiple bonds between carbon atoms), and the term “alkenyl” is used to refer to linear or branched substituents that are unsaturated (i.e., having at least one multiple bond between carbon atoms, and thus including materials including triple bonds between carbons). As discussed above, the C8-C24hydrocarbyl primary amine component comprises primary amines having only one C8-C24hydrocarbyl. Accordingly, a combination of C8-C24alkyl amine and primary C8-C24alkenyl amine would be understood to be a mixture of C8-C24 alkyl amines and primary C8-C24alkenyl amines. In some embodiments, the C8-C24hydrocarbyl primary amine component has a linear C8-C24hydrocarbyl group.

[0019] A variety of chain length distributions of the hydrocarbyl carbon chain can be used to prepare the polymer compositions of the disclosure. However, a substantial amount of the hydrocarbyl carbon chains can be of a particular range of chain lengths. For example, in various embodiments as described herein, at least 70 wt% of the C8-C24hydrocarbyl primary amine component has carbon chain lengths in the range of Cw-C22, e.g., at least 80 wt%, or at least 90 wt%. In some embodiments, at least 70 wt% of the C8-C24hydrocarbyl primary amine component has carbon chain lengths in the range of Ci4-C20, e.g., at least 80 wt%, or at least 90 wt%. For example, in some embodiments, at least 70 wt% of the C8-C24hydrocarbyl primary amine component has carbon chain lengths in the range of Ci6-C20, e.g., at least 80 wt%, or at least 90 wt%. In various embodiments, at least 70 wt% of the C8-C24hydrocarbyl primary amine component has carbon chain lengths of C , e.g., at least 80 wt%, or at least 90 wt%.

[0020] The person of ordinary skill in the art can, based on the present disclosure, select a relative amount of the C8-C24 hydrocarbyl primary amine component sufficient to improve the dispersibility of the resulting polymer composition in nonpolar media like the base oils typically used in lubricants. In various aspects, as described above, the reaction components comprise 30-60 parts by weight of the hydrocarbyl primary amine component, together with 35-60 parts by weight of the styrene / maleic anhydride copolymer and 0.5-5 parts by weight of the polyethyleneimine oligomer component. In various embodiments as otherwise described herein, the polymer composition is a reaction product of components comprising in the range of 32-60 parts by weight of the C8-C24hydrocarbyl primary amine component, e.g., in the range of 35-60 parts by weight, or in the range 37-60 parts by weight, or in the range of 40-60 parts by weight, or in the range of 42-60 parts by weight, or in the range of 45-60 parts by weight, or in the range of 47-60 parts by weight, or in the range of 50-60 parts by weight, or in the range of 52-60 parts by weight. In various embodiments, the polymer composition is a reaction product of components comprising in the range of 30-57 parts by weight of the C8-C24hydrocarbyl primary amine component, e.g., in the range of 32-57 parts by weight, or in the range of 35-57 parts by weight, or in the range of 40-57 parts by weight, or in the range of 42-57 parts by weight, or in the range of 45-57 parts by weight, or in the range of 47-57 parts by weight, or in the range of 50-57 parts by weight. In some embodiments, the polymer composition is a reaction product of components comprising in the range of 30-55 parts by weight of the C8-C24hydrocarbyl primary amine component, e.g., in the range of 32-55 parts by weight, or in the range of 35-55 parts by weight, or in the range of 40-55 parts by weight, or in the range of 42-55 parts by weight, or in the range of 45-55 parts by weight, or in the range of 47-55 parts by weight, or in the range of 50-55 parts by weight. For example, in some embodiments, the polymer composition is a reaction product of components comprising in the range of 30-52 parts by weight of the C8-C24hydrocarbyl primary amine component, e.g., in the range of 32-52 parts by weight, or in the range of 35-52 parts by weight, or in the range of 40-52 parts by weight, or in the range of 42-52 parts by weight, or in the range of 45-52 parts by weight.

[0021] As described above, polyethyleneimine oligomers are a reaction component for providing the polymer compositions described herein. A “polyetheyleneimine oligomer” is understood to refer to an oligomer of “ethylenimine,” i.e., an oligomer having the repeating unit (-NH-CH2-CH2-). The present inventors have determined that the use of the polyethyleneimine oligomers can impart advantageous dispersing properties to the polymer composition. The person of ordinary skill in the art will appreciate that a variety ofcompounds can be used to provide desirable dispersing properties. For example, in various embodiments as described herein, the polyethyleneimine oligomer component has a number-average degree of polymerization in the range of 2-8, e.g., in the range of 2-6, or 2- 5, or 3-8, or 3-6, or 3-5. In other embodiments, the polyethyleneimine oligomer component has a number-average degree of polymerization in the range of 4-20, e.g., in the range of 4- 15, or 4-10, or 4-8, or 7-20, or 7-15, or 7-10. In some embodiments, the polyethyleneimine oligomer component is linear (i.e., wherein each of the nitrogen atoms of the polyethyleneimine oligomer has no more than two ethylene substituents). In certain embodiments, the polyethyleneimine oligomer component is tetraethylenepentamine.

[0022] The person of ordinary skill in the art can, based on the present disclosure, select a relative amount of polyethyleneimine oligomer component sufficient to provide the resulting polymer composition with desirable dispersing properties. In various aspects, as described above, the reaction components comprise 0.5-5 parts by weight of the polyethyleneimine oligomer component together with 40-60 parts by weight of the hydrocarbyl primary amine component and 35-60 parts by weight of the styrene / maleic anhydride copolymer. In various embodiments of the present disclosure as described herein, the polymer composition is a reaction product of components comprising in the range of 0.5-4.5 parts by weight of the polyethyleneimine oligomer component, e.g., in the range of 0.5-4.0 parts by weight, or in the range of 0.5-3.5 parts by weight, or in the range of 0.5-3.0 parts by weight, or in the range of 0.5-2.5 parts by weight, or in the range of 0.5-2.0 parts per weight. For example, in various embodiments, the polymer composition is a reaction product of components comprising in the range of 1 .0-5.0 parts by weight of the polyethyleneimine oligomer component, e.g., in the range of 1 .0-4.5 parts by weight, or in the range of 1 .0-4.0 parts by weight, or in the range of 1 .0-3.5 parts by weight, or in the range of 1 .0-3.0 parts by weight, or in the range of 1 .0-2.5 parts by weight, or in the range of 1 .0-2.0 parts by weight. In some embodiments, the polymer composition is a reaction product of components comprising in the range of 1 .5-5.0 parts by weight of the polyethyleneimine oligomer component, e.g., in the range of 1 .5-4.5 parts by weight, or in the range of 1 .5-4.0 parts by weight, or in the range of 1 .5-3.5 parts by weight, or in the range of 1 .5-3.0 parts by weight, or in the range of 1 .5-2.5 parts by weight.

[0023] As described above, the present inventors have found that the C8-C24 hydrocarbyl primary amine residues can advantageously improve the dispersibility of the resulting polymer composition in base oils, and the polyethyleneimine oligomer residues can impart advantageous dispersing properties to the polymer composition. The C8-C24 hydrocarbyl primary amine residues and the polyethyleneimine oligomer residues can be included in a variety of relative amounts. But the present inventors have found that it can be desirable inmany embodiments to have a relatively high ratio of C8-C24 hydrocarbyl primary amine component to polyethyleneimine oligomer component. In various embodiments as described herein, the molar ratio of the C8-C24 hydrocarbyl primary amine component to the polyethyleneimine oligomer component is at least 10:1 , e.g., at least 12:1. In various embodiments, the molar ratio of the C8-C24hydrocarbyl primary amine component to the polyethyleneimine oligomer component is at least 15:1 , e.g., at least 17:1 . In various embodiments as described herein, the molar ratio of the C8-C24hydrocarbyl primary amine component to the polyethyleneimine oligomer component is in the range of 10:1 to 30:1 , e.g., in the range of 10:1 to 25:1 , or in the range of 10:1 to 20:1 . In various embodiments as described herein, the molar ratio of the C8-C24hydrocarbyl primary amine component to the polyethyleneimine oligomer component is in the range of 12:1 to 30:1 , e.g., in the range of 12:1 to 25:1 , or in the range of 12:1 to 20:1 . In various embodiments as described herein, the molar ratio of the C8-C24hydrocarbyl primary amine component to the polyethyleneimine oligomer component is in the range of 15:1 to 30:1 , e.g., in the range of 15:1 to 25:1 , or in the range of 15:1 to 20:1 . In various embodiments as described herein, the molar ratio of the C8-C24hydrocarbyl primary amine component to the polyethyleneimine oligomer component is in the range of 17:1 to 30:1 , e.g., in the range of 17:1 to 25:1 , or in the range of 17:1 to 20:1.

[0024] Similarly, the polymer composition can comprise relative amounts of C8-C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a variety of ratios. In various embodiments, the polymer composition comprises C8-C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio of at least 10:1 , e.g., at least 12:1. In various embodiments, the polymer composition comprises C8-C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio of or at least 15:1 , or at least 17:1 . In various embodiments as described herein, the polymer composition comprises C8-C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio in the range of 10:1 to 30:1 , e.g., in the range of 10:1 to 25:1 , or in the range of 10:1 to 20:1 . In various embodiments as described herein, the polymer composition comprises C8-C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio in the range of 12:1 to 30:1 , e.g., in the range of 12:1 to 25:1 , or in the range of 12:1 to 20:1 . In various embodiments as described herein, the polymer composition comprises C8-C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio in the range of 15:1 to 30:1 , e.g., in the range of 15:1 to 25:1 , or in the range of 15:1 to 20:1 . In various embodiments as described herein, the polymer composition comprises C8-C24hydrocarbyl primary amine residues andpolyethyleneimine oligomer residues in a molar ratio in the range of 17:1 to 30:1 , e.g., in the range of 17:1 to 25:1 , or in the range of 17:1 to 20:1.

[0025] The polymer compositions described herein can be substantially formed of residues of the three components described above. As noted above, in various aspects of the disclosure a total amount of styrene / maleic anhydride copolymer residues, C8-C24 hydrocarbyl primary amine residues and polyethyleneimine oligomer residues is at least 80 wt% of the polymer composition. In various embodiments of present disclosure as described herein, the total amount of the styrene residues, maleic anhydride residues, C8-C24 hydrocarbyl primary amine residues, and polyethyleneimine oligomer residues is at least 85 wt% of the total weight of the polymer composition, e.g., at least 90 wt%. For example, in various embodiments of present disclosure as described herein, the total amount of styrene residues, maleic anhydride residues, C8-C24 hydrocarbyl primary amine residues, and polyethyleneimine oligomer residues is at least 95 wt% of the total weight of the polymer composition, e.g., at least 98 wt%.

[0026] The polymer compositions described herein can have a variety of weight-average molecular weights. For example, in various embodiments as described herein, the weight-average molecular weight of the polymer composition is in the range of 15-50 kDa, e.g., in the range of 15-45 kDa, or in the range of 15-40 kDa, or in the range of 20-50 kDa, or in the range of 20-45 kDa, or in the range of 20-40 kDa. For example, in some embodiments, the weight-average molecular weight of the polymer composition is in the range of 25-50 kDa, or in the range of 25-45 kDa, or in the range of 25-40 kDa, or in the range of 30-50 kDa, or in the range of 30-45 kDa, or in the range of 30-40 kDa. The weightaverage molecular weight of the polymer composition can be determined by performing GPC on Agilent PLgel columns using THF as the mobile phase and narrow molecular weight polystyrene as standards.

[0027] The person of ordinary skill in the art will appreciate that the unreacted maleic anhydride residues of the styrene / maleic anhydride copolymer can hydrolyze into carboxylates, which can increase the acid value of a polymer composition. However, as described above, the C8-C24 hydrocarbyl primary amine component and polyethyleneimine oligomer component are nitrogen-containing compounds that can undergo condensation reactions with the maleic anhydride residues of the styrene / maleic anhydride copolymer to provide amides or imides such as maleimides. Accordingly, the polymer compositions described herein can desirably have low acid values. For example, in various embodiments as described herein, the polymer composition has an acid value of no more than 20 mg KOH / g, e.g., no more than 18 mg KOH / g, no more than 16 mg KOH / g, no more than 14 mg KOH / g, no more than 12 mg KOH / g, or no more than 10 mg KOH / g. In some embodiments,the polymer composition has an acid value that is no more than 5% of the acid value of the styrene / maleic anhydride copolymer, e.g., no more than 4%, or no more than 3%, or no more than 2%.

[0028] As described above, the polymer compositions described herein are a reaction product from the condensation of the C8-C24 hydrocarbyl primary amine component and polyethyleneimine oligomer component with the styrene / maleic anhydride copolymer. The person of ordinary skill in the art is familiar with the condensation reactions that are used to react amines with maleic anhydrides, and can adapt such procedures to make the polymer compositions described herein.

[0029] A suitable solvent for performing such a condensation reaction can have a sufficiently high boiling point such that adequate heat can be provided to the condensation reaction. However, a suitable solvent can also have a boiling point such that it can be substantially removed after the condensation reaction. As used herein, the term “solvent” refers to a liquid media that is chemically inert to the reaction that is being performed therein. Accordingly, in various embodiments as described herein, the polymer composition is dispersed in an aromatic hydrocarbon solvent having an atmospheric pressure boiling point in the range of 120-180 °C.

[0030] Upon the completion of the condensation reaction, the solvent can be removed from the polymer composition (e.g., by means of heating, negative pressure, or a combination thereof). Accordingly, polymer compositions of the disclosure can comprise small amounts of the solvent. For example, in some embodiments, the polymer composition has no more than 3 wt% of solvents having an atmospheric pressure boiling point less than 180 °C, e.g., no more than 2 wt%, or no more than 1 wt%, based on the total weight of the polymer composition. In some embodiments, the polymer composition has no more than 3 wt% of solvents having an atmospheric pressure boiling point in the range of 120-180 °C, e.g., no more than 2 wt%, or no more than 1 wt%, based on the total weight of the polymer composition.

[0031] Lubricants

[0032] In another aspect, the present disclosure provides a lubricant including: a base oil, and the polymer composition described herein, present in an amount in the range of 0.1- 5 wt% of a total weight of the lubricant, as determined on a solids basis (i.e., excluding any solvent having a boiling point of 180 °C or less).

[0033] The present inventors have found that the inclusion of a polymer composition as described herein in a lubricant advantageously imparts desirable properties (e.g., dispersing properties) to the lubricant while minimizing undesirable increases to kinematic viscosity.Accordingly, lubricants including the polymer composition described herein can be prepared with Group II and / or Group III base oils. As used herein, “Group II base oil” refers to a base oil that comprises at least 90% saturates and no more than 0.03% sulfur on a weight basis, and having a viscosity index (VI) in the range of 80 to 120. As used herein, “Group III base oil” refers to a base oil that comprises at least 90% saturates and no more than 0.03% sulfur on a weight basis, and having a VI of at least 120. For example, in various embodiments, the base oil of the lubricant comprises (or is) a Group II base oil and / or a Group III base oil. In some embodiments, the base oil of the lubricant comprises (or is) a Group III base oil. In various embodiments of the present disclosure as described herein, the total amount of Group II base oil and Group III base oil in the lubricant is in the range of 40-90 wt% of the total weight of the lubricant, e.g., or in the range of 50-85 wt%, or in the range of 40-80 wt%, or in the range of 40-70 wt%, or in the range of 50-90 wt%, or in the range of 50-85 wt%, or in the range of 50-80 wt%, or in the range of 50-70 wt%. In various embodiments of the present disclosure as described herein, the total amount of Group II base oil and Group III base oil in the lubricant is at least 80 wt%, e.g., in the range of 80-90 wt%, or in the range of 80-85 wt%. In various embodiments of the present disclosure as described herein, the total amount of Group II base oil and Group III base oil in the lubricant is at least 85 wt%, e.g., in the range of 85-90 wt%.

[0034] As described above, the lubricants described herein have a low kinematic viscosity due to the polymer composition included therein. Accordingly, the lubricants described herein do not require the addition of Group IV base oils to further lower the kinematic viscosity. As used herein, “Group IV base oils” refer to a synthetic oil (e.g., polyalphaolefins (PAG)), that have a VI in the range of 125-200. For example, in various embodiments as otherwise described herein, Group IV base oil is present in the lubricant in an amount of no more than 10 wt% of the total weight of the lubricant, e.g., no more than 5 wt%, or no more than 2 wt%, or no more than 1 wt%. In some embodiments, substantially no Group IV base oil is present in the lubricant.

[0035] However, the low kinematic viscosity of the lubricants described herein does not necessarily preclude the inclusion Group IV base oils therein. The person of ordinary skill can prepare lubricants of the disclosure that include Group IV base oils, e.g., for use in applications that require high performance lubricants. In some embodiments as described herein, the base oil of the lubricant comprises a Group IV base oil in an amount in the range of 10-30 wt% of the total weight of the lubricant, e.g., in the range of 15-25 wt%. In some embodiments, the Group IV base oil is a polyalphaolefin.

[0036] Due to the beneficial properties that the polymer composition described herein can impart upon the lubricant, the lubricant can comprise substantially of base oil. In variousembodiments as described herein, a total amount of base oil in the lubricant is in the range of 40-90 wt% of the total weight of the lubricant, e.g., or in the range of 50-85 wt%, or in the range of 40-80 wt%, or in the range of 40-70 wt%, or in the range of 50-90 wt%, or in the range of 50-85 wt%, or in the range of 50-80 wt%, or in the range of 50-70 wt%. In various embodiments of the present disclosure as described herein, the total amount of base oil in the lubricant is at least 80 wt%, e.g., in the range of 80-90 wt%, or in the range of 80-85 wt%. In various embodiments of the present disclosure as described herein, the total amount of base oil in the lubricant is at least 85 wt%, e.g., in the range of 85-90 wt%.

[0037] The person of ordinary skill in the art can determine an appropriate amount of polymer composition to include in the lubricant to achieve desirable properties. For example, in various embodiments as described herein, the polymer composition is present in an amount in the range of 0.1-4.5 wt% of the total weight of the lubricant, e.g., in the range of 0.1 -4.0 wt%, or in the range of 0.1 -3.5 wt%, or in the range of 0.1 -3.0 wt%, or in the range of 0.1-2.5 wt%, or in the range of 0.1-2.0 wt%, or in the range of 0.1-1 .5 wt%. In some embodiments as described herein, the polymer composition is present in an amount in the range of 0.3-5.0 wt% of the total weight of the lubricant, e.g., in the range of 0.3-4.5 wt%, or in the range of 0.3-4.0 wt%, or in the range of 0.3-3.5 wt%, or in the range of 0.3-3.0 wt%, or in the range of 0.3-2.5 wt%, or in the range of 0.3-2.0 wt%, or in the range of 0.3-1 .5 wt%. In some embodiments, the polymer composition is present in an amount in the range of 0.5-5.0 wt% of the total weight of the lubricant, e.g., in the range of 0.5-4.5 wt%, or in the range of 0.5-4.0 wt%, or in the range of 0.5-3.5 wt%, or in the range of 0.5-3.0 wt%, or in the range of 0.5-2.5 wt%, or in the range of 0.5-2.0 wt%, or in the range of 0.5-1 .5 wt%. For example, in various embodiments, the polymer composition is present in an amount in the range of 0.5- 5.0 wt% of the total weight of the lubricant, e.g., in the range of 0.7-4.5 wt%, or in the range of 0.7-4.0 wt%, or in the range of 0.7-3.5 wt%, or in the range of 0.7-3.0 wt%, or in the range of 0.7-2.5 wt%, or in the range of 0.7-2.0 wt%, or in the range of 0.7-1 .5 wt%.

[0038] Of course, the lubricant described herein can comprise additional components, such as one or more additional dispersants. As would be understood by the skilled person, and by claim differentiation, the term "additional dispersant" refers to other compounds with dispersing properties that are not the polymer composition; the person of ordinary skill in the art is familiar with the use of dispersants in lubricating compositions. For example, in various embodiments of the present disclosure as described herein, the lubricant comprises one or more additional dispersants, e.g., one, two, three, or four additional dispersants. In various embodiments, the lubricant comprises one or more additional dispersants in an amount up to 20 wt% of the total weight of the lubricant, e.g., up to 15 wt%, or up to 10 wt%, or in the range of 1-20 wt%, or 1-15 wt%, or 1-10 wt%, or 2-20 wt%, or 2-10 wt%, or 2-15 wt%, or 3-20 wt%, or 3-15 wt%, or 3-12 wt%, or 3-10 wt%, or 5-20 wt%, or 5-15 wt%, or 5-12 wt%, or 5-10 wt%.

[0039] As described above, the inclusion of the polymer composition described herein in a lubricant can minimize increases in the kinematic viscosity of the lubricant. In various embodiments as described herein, the lubricant has a kinematic viscosity at 100 °C of no more than 10 cSt, e.g., no more than 9 cSt, or no more than 8 cSt, or no more than 7 cSt. For example, in various embodiments, the lubricant has a kinematic viscosity at 100 °C in the range of 4-10 cSt, e.g., in the range of 4-8 cSt, or in the range of 5-9 cSt, or in the range of 5-7 cSt.

[0040] In some embodiments, the lubricant has a kinematic viscosity at 40 °C of no more than 40 cSt, e.g., no more than 38 cSt, or no more than 35 cSt, or no more than 32 cSt, or no more than 30 cSt, or no more than 28 cSt. For example, in some embodiments, the lubricant has a kinematic viscosity at 40 °C in the range of 18-40 cSt, e.g., in the range of 18-35 cSt, or in the range of 18-30 cSt, or in the range of 18-28 cSt, or in the range of 20-40 cSt, or in the range of 20-35 cSt, or in the range of 20-30 cSt, or in the range of 25-40 cSt, or in the range of 25-35 cSt, or in the range of 25-30 cSt.

[0041] In various embodiments of the present disclosure, the lubricant has a kinematic viscosity at 20 °C of no more than 80 cSt, e.g., no more than 78 cSt, or no more than 75 cSt, or no more than 73 cSt, or no more than 70 cSt, or no more than 68 cSt. For example, in various embodiments, the lubricant has a kinematic viscosity at 20 °C in the range of 40-80 cSt, e.g., in the range of 40-75 cSt, or in the range of 40-70 cSt, or in the range of 45-80 cSt, or in the range of 45-75 cSt, or in the range of 45-70 cSt, or in the range of 50-80 cSt or in the range of 50-75 cSt, or in the range of 50-70 cSt.

[0042] The inclusion of the polymer composition as described herein inside the lubricant can impart various beneficial properties to the lubricant, thus in many embodiments obviating the need for the inclusion of certain lubricant additives.

[0043] For example, the inclusion of the polymer composition as described herein can reduce the amount of anti-oxidants needed for the lubricant to have a desired performance. For example, in various embodiments, the lubricant comprises no more than 2.5 wt%, e.g., no more than 2.4 wt%, or no more than 2.3 wt%, or no more than 2.2 wt%, or no more than 2.1 wt%, or no more than 2.0 wt%, of anti-oxidants. In various embodiments, the lubricant comprises no more than 1 .5 wt%, e.g., no more than 1 .4 wt%, or no more than 1 .3 wt%, or no more than 1 .2 wt%, or no more than 1 .1 wt%, or no more than 1 .0 wt%, of aminic antioxidants. As used herein, the term “aminic anti-oxidant” is understood to refer to an antioxidant comprising an oxidizable nitrogen atom.

[0044] As noted above, the polymer composition described herein has dispersing properties. While additional dispersants can be used in the lubricant, the present inventors have determined that inclusion of the polymer composition as described herein can reduce the amount of additional dispersants needed for the lubricant to have a desired performance. As would be understood by the skilled person, and by claim differentiation, the term "additional dispersant" refers to other compounds with dispersing properties that are not the polymer composition; the person of ordinary skill in the art is familiar with the use of dispersants in lubricating compositions. In various embodiments, the lubricant comprises no more than 6.5 wt%, e.g., no more than 6.4 wt%, or no more than 6.3 wt%, or no more than 6.2 wt%, or no more than 6.1 wt%, or no more than 6.0 wt%, of additional dispersants. In various embodiments, the lubricant comprises no more than 2.2 wt%, e.g., no more than 2.1 wt%, or no more than 2.0 wt%, or no more than 1 .9 wt%, or no more than 1 .8 wt%, or no more than 1.7 wt%, of a non-borated dispersant. As used herein, the term “non-borated dispersant” is understood to refer to a dispersant lacking boron atoms. In various embodiments, the lubricant comprises no more than 3.4 wt%, e.g., no more than 3.2 wt%, or no more than 3.0 wt%, or no more than 2.8 wt%, of a high molecular weight dispersant. As used herein, the term “high molecular weight dispersant” is understood to refer to an additional dispersant having a weight average molecular weight in the range of 2000-3300 Da.

[0045] The present inventors have found that inclusion of the polymer composition as described herein can reduce the amount of corrosion inhibitors needed for the lubricant to have a desired performance. In various embodiments, the lubricant comprises no more than 0.6 wt%, e.g., no more than 0.5 wt%, or no more than 0.4 wt%, or no more than 0.3 wt%, or no more than 0.2 wt%, or no more than 0.1 wt%, or no more than 0.05 wt% of corrosion inhibitors. In various embodiments, the lubricant comprises substantially no corrosion inhibitors.

[0046] Accordingly, the lubricants described herein can have a desired performance level with a reduced total amount of non-polymeric additives. In various embodiments, the lubricant comprises no more than 15 wt%, e.g., no more than 14 wt%, or no more than 13 wt%, or no more than 12 wt%, of non-polymeric additives. As used herein, the term “non- polymeric additives” is understood to refer to chemical compounds in the lubricant having a molecular weight of no more than 5 kDa that are not the base oil or the polymer composition.

[0047] The lubricant as described herein can be used in a variety of applications, as determined by the person of ordinary skill in the art. For example, the lubricant as described herein can be used as a lubricant for an internal combustion engine. Accordingly, in various embodiments as described herein, the lubricant is disposed inside an internal combustionengine. The present inventors have found that lubricants comprising the polymer compositions described herein have similar performance or improved performance compared to an otherwise identical lubricant lacking the polymer composition when subjected to testing inside the internal combustion engine, such as in a High Temperature Corrosion Bench Test (HTCBT), as described by method ASTM D6594. The “otherwise identical lubricant” is understood to otherwise have the same proportions materials other than base oil, with the amount of the polymer composition of the disclosure replaced by base oil. For example, for a lubricant of the disclosure having 75 wt% base oil, 24 wt% additional components, and 1 wt% of the polymer composition disclosed herein, an “otherwise identical lubricant” would have 76 wt% base oil and 24 wt% additional components with no polymer composition of the disclosure.

[0048] For example, when subjected to a HTCBT, the lubricant described herein can have a similar copper strip rating compared to an otherwise identical lubricant lacking the polymer composition. The person of ordinary skill in the art will appreciate that the copper string rating is a rating scale from 1a (i.e., light tarnish) to 4b (i.e., corrosion), as outlined in ASTM D130, describing the amount of tarnish or corrosion on the surface of copper. Accordingly, in various embodiments as described herein, the lubricant exhibits at least as good a copper string rating as an otherwise identical lubricant when subjected to a HTCBT, as determined by ASTM D6594 (i.e., wherein the lubricant and otherwise identical lubricant both exhibit a copper string rating of 3a). In various embodiments, the lubricant exhibits a copper string rating of no worse than 3a. For example, in some embodiments, the lubricant exhibits a copper string rating of 3a.

[0049] The lubricant described herein can also exhibit similar tin corrosion compared to an otherwise identical lubricant lacking the polymer composition when subjected to HTCBT. For example, in various embodiments as described herein, the lubricant exhibits an increase in tin concentration of no more than 10 mg / kg, e.g., no more than 5 mg / kg, or no more than 2 mg / kg, or no more than 1 mg / kg, or no more than 0.5 mg / kg, when subjected to a HTCBT. In some embodiments as described herein, the lubricant exhibits a change in Sn concentration that is no more than 120% of a change in tin concentration exhibited by an otherwise identical lubricant lacking the polymer composition when subjected to a HTCBT, e.g., no more than 115%, or no more than 110%, or no more than 105%. In some embodiments, the change in tin concentration is in the range of 80-120% of a change in tin concentration exhibited by an otherwise identical lubricant lacking the polymer composition when subjected to a HTCBT, e.g., in the range of 85-115%, or in the range of 90-110%, or in the range of 95-105%.

[0050] The inclusion of the polymer composition in the lubricant can also improve the performance of the lubricant when subjected to a HTCBT. For example, the inclusion of the polymer composition of the disclosure can decrease the lead corrosion exhibited by the lubricant. In various embodiments described herein, the lubricant exhibits a change in lead concentration of no more than 50 mg / kg when subjected to a HTCBT, e.g., no more than 40 mg / kg, or no more than 30 mg / kg, or no more than 20 mg / kg, or no more than 10 mg / kg, or no more than 5 mg / kg. For example, in various embodiments described herein, the lubricant exhibits a change in lead concentration in the range of 0.01-10 mg / kg when subjected to a HTCBT, e.g., in the range of 0.05-10 mg / kg, or in the range of 0.1-10 ppm, or in the range of 0.5-10 mg / kg, or in the range of 1-10 mg / kg, or in the range of 0.01-5 mg / kg, or in the range of 0.05-5 mg / kg, or in the range of 0.1-5 mg / kg, or in the range of 0.5-5 mg / kg, or in the range of 1-5 mg / kg, or in the range of 0.01-3 mg / kg, or in the range of 0.05-3 mg / kg, or in the range of 0.1-3 mg / kg, or in the range of 1-3 kg. In some embodiments, the lubricant exhibits a change in lead corrosion that is no more than 50% of a change in lead concentration exhibited by an otherwise identical lubricant lacking the polymer composition when subjected to a HTCBT, e.g., no more than 40%, or no more than 30%, or no more than 25%, or no more than 20%, or no more than 15%, or no more than 10%, or no more than 5%.

[0051] The inclusion of the polymer composition in the lubricant can also decrease the copper corrosion exhibited by the lubricant. In various embodiments described herein, the lubricant exhibits a change in copper concentration of no more than 80 ppm when subjected to a HTCBT, e.g., no more than 70 ppm, or no more than 60 ppm, or no more than 50 ppm, or no more than 45 ppm, or no more than 40 ppm. For example, in various embodiments described herein, the lubricant exhibits a change in copper concentration in the range of 5- 50 ppm when subjected to a HTCBT, e.g., in the range of 5-45 ppm, or in the range of 5-40 ppm, or in the range of 10-50 ppm, or in the range of 10-45 ppm, or in the range of 10-40 ppm, or in the range of 15-50 ppm, or in the range of 15-45 ppm, or in the range of 15-40 ppm. In some embodiments, the lubricant exhibits a change in copper concentration that is no more than 80% of a change in lead concentration exhibited by an otherwise identical lubricant lacking the polymer composition when subjected to a HTCBT, e.g., no more than 70%, or no more than 60%, or no more than 55%, or no more than 50%, or no more than 45%, or no more than 40%.

[0052] As described above, the lubricants of the disclosure can be used as a lubricant for an internal combustion engine. Accordingly, the lubricants of the disclosure can rheological properties sufficient for various motor oil viscosity grades. Motor oil viscosity grades are defined by the specification known as API 1509 (as of the priority date of the present application), and the person of ordinary skill in the art will appreciate that modernmotor oils can be multi-grade oils, wherein their viscosities at both high and low temperatures are measured. In various embodiments as described herein, the lubricant meets the requirements for a 0W-20 oil. For example, in various embodiments, the lubricant meets the requirements for a OW-16 oil. In some embodiments, the lubricant meets the requirements for a OW-12 oil. For example, in some embodiments, the lubricant meets the requirements for a OW-8 oil.

[0053] Methods and Uses in Lubrication

[0054] Accordingly, another aspect of the disclosure is the use of a lubricant as described herein in the lubrication of an internal combustion engine.

[0055] And another aspect of the disclosure is a method for lubricating an internal combustion engine, the method providing supplying a lubricant as described herein to the internal combustion engine, and operating the internal combustion engine with the lubricant supplied thereto.

[0056] The internal combustion engine can be, e.g., an engine of a vehicle, such as a car, a truck, or a motorcycle.EXAMPLES

[0057] The Examples that follow are illustrative of specific embodiments of the catalyst materials of the disclosure, and various uses thereof. They are set forth for explanatory purposes only, and are not to be taken as limiting the scope of the disclosure

[0058] Polymer Composition

[0059] An exemplary polymer composition was formed as follows:

[0060] A 4-neck 3 L reaction vessel was fitted with a mechanical stirrer, temperature probe, septum, and a Dean-Stark trap with an N2line. Poly(styrene-co-maleic anhydride) (XIRAN® 1000, molar ratio styrene:maleic anhydride ~ 1 :1 , 309.9 g, 1350 mmol), octadecylamine (Armeen 18D, 328.4 g, 1215 mmol), and an aromatic solvent (A150, 1119 g, 1350 mL) were added to the reaction vessel. The reaction was stirred at 400 rpm and heated at reflux (about 180-190 °C) for 2 hours, during which time 23.8 mL of water was collected from the Dean-Stark trap. The reaction was cooled to 160 °C.Tetraethylenepentamine (“TEPA,” 12.78 g, 67.6 mmol) was added with rinsing into the vessel with 10 mL of A150. The reaction mixture was heated at reflex for 4.5 hours. Then, the reaction vessel was set to 100 °C / 200 rpm and the mixture allowed to cool. By this time, another 3.2 mL water was collected in the Dean-Stark trap.

[0061] To distill off the solvent, the reaction was transferred to a 2-neck 2 L reaction vessel fitted with a distillation head and a N2 / vacuum line. The reaction was set to 200 °C / 400 rpm for 1 hour. Vacuum was applied at 280 torr, and the pressure was slowly lowered to 63-65 torr. After 2 hours, the vacuum was released under a stream of N2. After 3 hours, the product is poured out, providing 586.5 g of SMAI-TEPA as a brittle dark brown solid; this was used as the SMAI-TEPA in Examples 1 and 2. 41 .6 g of SMAI-TEPA remained in the reaction vessel. 1216.5 g of distillate was recovered during the distillation. The SMAI-TEPA product had on the order of 1 wt% residual solvent, about 80 ppm residual octadecylamine, and less than 50 ppm residual tetraethylenepentamine, as determined by chromatographic analysis. The weight-average molecular weight of the SMAI-TEPA product was about 30 kDa and the number-average molecular weight was about 10 kDa, both determined by gel permeation chromatography on Agilent PLgel columns at 35 °C using THF as the mobile phase and narrow molecular weight polystyrene as standards.

[0062] Example 1 : OW-12 Engine Oil

[0063] Formulation I was prepared by including a styrene / maleic anhydride imide tetraethylenepentamine (SMAI-TEPA) in an ultra-low viscosity engine oil. Table 1 below summarizes the components of Formulation 1 in comparison with Baseline Formulation I, which represents a OW-12 engine oil prepared using conventional additive technology.

[0064] Table 1 .

[0065] The present inventors found that the dispersing properties of SMAI-TEPA allows for the preparation of a 0W-12 engine oil without the need for certain conventional additives, such as anti-wear dispersants. The dispersing properties of SMAI-TEPA also allows for a 3.2 wt% reduction in the amount of the additive package as compared to the baseline formulation. Advantageously, the inclusion of SMAI-TEPA allows for Formulation I to meetthe viscosity requirements of a OW-12 without the inclusion of a Group IV base oil (e.g., Synfluid PAO 2.5). The properties of Formulation I as they relate to the requirements of OW- 12 are summarized below in Table 2.

[0066] Table 2.

[0067] Formulation I exhibits a KV100 of 6.041 cSt, a KV40 of 27.73 cSt, and a KV20 of 62.67 cSt, as determined using ASTM 445. The kinematic viscosity values exhibited by Formulation I are comparable to the baseline formulation, which includes a Group IV base oil, and Formulation I largely fulfills the requirements of a OW-12 engine oil. Additionally, the CCS and HTHS exhibited by Formulation I, as determined by ASTM D5293 and ASTM D4683, respectively, are well within the limitations of a OW-12 engine oil.

[0068] Example 2: Internal Combustion Engine Tests

[0069] The Baseline Formulation and Formulation I were each subjected to various tests to evaluate their performance in an internal combustion engine, including: a high temperature corrosion bench test (HTCBT) according to ASTM D6594; a thermo-oxidation engine oil simulation test (TEOST) according to ASTM D6335;a moderately high temperature thermo-oxidation engine oil simulation test (MTEOST) according to ASTM D7097; pressure differential scanning calorimetry (PDSC) according to ASTM D6186; and a micro-coking test (MCT) according to GFC LU 27-A-13.

[0070] The results of these test are summarized below in Table 3.

[0071] Table 3.

[0072] In some aspects, Formulation I has similar performance to the Baseline Formulation while still exhibiting the desirable kinematic viscosity properties. For example, when subjected to the HTCBT, both formulations provide identical copper string ratings of “3a”, and both formulations do not cause any corrosion of Sn (i.e., 0 mg / kg change in Sn concentration). However, in other aspects, Formulation I provides improved performance compared to the Baseline Formulation when subjected to the HTCBT. For example, Formulation I exhibits greatly reduced copper corrosion properties (i.e., 73% reduction in change of Cu concentration) and lead corrosion properties (i.e., a 99% reduction in change of Pb concentration) compared to the Baseline Formulation.

[0073] Example 3: Engine Oil Formulation

[0074] Formulation II was prepared by including a styrene / maleic anhydride imide tetraethylenepentamine (SMAI-TEPA) in an engine oil. Table 2 below summarizes the components of Formulation II in comparison with Baseline Formulation II, which represents an engine oil prepared using conventional additive technology.

[0075] Table 4.

[0076] Compared to the Baseline Formulation II, Formulation II contains no Group IV base oil (SynFluid PAO 2.5), contains 2 wt% less total dispersants, 0.3 wt% less aminic anti- oxidasnt, and no corrosion inhibitor.

[0077] Example 4: Engine Oil Sludge Tests

[0078] The various engine oil formulations were subjected to a CEC-L-107 engine oil performance tests, which evaluates how well an oil prevents sludge buildup in engines. The results of the test are summarized below.

[0079] Accordingly, Formulations I and II containing SMAI-TEPA were able to pass the sludge rating test. The inclusion of SMAI-TEPA allows for the formulations to pass the CEC-L-107 test even in the absence of Group IV base oils and corrosion inhibitors, as well as reduced amounts of dispersants and anti-oxidants.

[0080] Various aspects of the disclosure are illustrated by the following enumerated embodiments, which may be combined in any number and in any combination not technically or logically inconsistent:Embodiment 1 . A polymer composition that is a reaction product of components comprising:35-60 parts by weight of a styrene / maleic anhydride copolymer, wherein the styrene / maleic anhydride copolymer comprises:40-80 wt% styrene residues, and20-60 wt% maleic anhydride residues, each based on a total weight of the styrene / maleic anhydride copolymer, at least 80 wt% of the styrene / maleic anhydride copolymer being formed of residues of styrene and maleic anhydride;30-60 parts by weight of a C8-C24 hydrocarbyl primary amine component; and 0.5-5 parts by weight of a polyethyleneimine oligomer component, wherein a total amount of styrene residues, maleic anhydride residues, C8-C24 hydrocarbyl primary amine residues and polyethyleneimine oligomer residues is in the range of at least 80 wt% of the polymer composition.Embodiment 2. The polymer composition of embodiment 1 , wherein the styrene / maleic anhydride copolymer comprises in the range of 40-75 wt% styrene residues, e.g., in the range of 40-70 wt%, or in the range of 40-65 wt%, or in the range of 40-60 wt%, or in the range of 40-55 wt% styrene residues, based on the total weight of the styrene / maleic anhydride copolymer.Embodiment 3. The polymer composition of embodiment 1 , wherein the styrene / maleic anhydride copolymer comprises in the range of 45-80 wt% styrene residues, e.g., in the range of 45-75 wt%, or in the range of 45-70 wt%, or in the range of 45-65 wt%, or in the range of 45-60 wt%, or in the range of 45-55 wt% styrene residues, based on the total weight of the styrene / maleic anhydride copolymer.Embodiment 4. The polymer composition of embodiment 1 , wherein the styrene / maleic anhydride copolymer comprises in the range of 50-80 wt% styrene residues, e.g., in the range of 50-75 wt%, or in the range of 50-70 wt%, or in the range of 50-65 wt%, or in the range of 50-60 wt% styrene residues, based on the total weight of the styrene / maleic anhydride copolymer.Embodiment 5. The polymer composition of embodiment 1 , wherein the styrene / maleic anhydride copolymer comprises in the range of 55-80 wt% styrene, e.g., in the range of 55-75 wt%, or in the range of 55-70 wt%, or in the range of 55-65 wt% styrene residues, based on the total weight of the styrene / maleic anhydride copolymer.Embodiment 6. The polymer composition of any of embodiments 1-5, wherein the styrene / maleic anhydride copolymer comprises in the range of 25-60 wt% maleic anhydride residues, e.g., in the range of 30-60 wt%, or in the range of 35-60 wt%, or in the range of 40- 60 wt%, or in the range of 45-60 wt% maleic anhydride residues, based on the total weight of the styrene / maleic anhydride copolymer.Embodiment 7. The polymer composition of any of embodiments 1-5, wherein the styrene / maleic anhydride copolymer comprises in the range of 20-55 wt% maleic anhydride residues, e.g., in the range of 25-55 wt%, or 30-55 wt%, or in the range of 35-55 wt%, or in the range of 40-55 wt%, or in the range of 45-55 wt% maleic anhydride residues, based on the total weight of the styrene / maleic anhydride copolymer.Embodiment 8. The polymer composition of any of embodiments 1-6, wherein the styrene / maleic anhydride copolymer comprises in the range of 20-50 wt% maleic anhydride residues, e.g., in the range of 25-50 wt%, or 30-50 wt%, or in the range of 35-50 wt%, or in the range of 40-50 wt% maleic anhydride residues, based on the total weight of the styrene / maleic anhydride copolymer.Embodiment 9. The polymer composition of any of embodiments 1-6, wherein the styrene / maleic anhydride copolymer comprises in the range of 20-45 wt% maleic anhydrideresidues, e.g., in the range of 25-45 wt%, or 30-45 wt%, or in the range of 35-45 wt% maleic anhydride residues, based on the total weight of the styrene / maleic anhydride copolymer.Embodiment 10. The copolymer composition of any of embodiments 1-9, wherein at least 90 wt%, e.g., at least 95 wt%, of the total weight of the styrene / maleic anhydride copolymer is formed of styrene and maleic anhydride residues.Embodiment 11. The copolymer composition of any of embodiments 1-9, wherein at least 98 wt%, e.g., at least 99 wt%, of the total weight of the styrene / maleic anhydride copolymer is formed of styrene and maleic anhydride residues.Embodiment 12. The polymer composition of any of embodiments 1-11 , wherein the styrene / maleic anhydride copolymer has a weight-average molecular weight in the range of 2,000 to 20,000 g / mol, e.g., in the range of 2,000 to 15,000 g / mol, or in the range of 2,000 to 10,000 g / mol, or in the range of 2,000 to 7,000 g / mol, or in the range of 4,000 to 20,000 g / mol, or in the range of 4,000 to 15,000 g / mol, or in the range of 4,000 to 10,000 g / mol, or in the range of 4,000 to 7,000 g / mol, as determined by gel permeation chromatography.Embodiment 13. The polymer composition of any of embodiments 1-11 , wherein the styrene / maleic anhydride copolymer has a weight-average molecular weight in the range of 3,000 to 7,000 g / mol, e.g., in the range of 3,500 to 7,000 g / mol, or in the range of 4,000 to 7,000 g / mol, or in the range of 4,500 to 7,000 g / mol, as determined by gel permeation chromatography.Embodiment 14. The polymer composition of any of embodiments 1-13, that is a reaction product of components comprising 40-60 parts by weight of the styrene / maleic anhydride copolymer, e.g., in the range of 45-60 parts by weight, or in the range of 50-60 parts by weight, or in the range of 55-60 parts by weight.Embodiment 15. The polymer composition of any of embodiments 1-13, that is a reaction product of components comprising 35-55 parts by weight of the styrene / maleic anhydride copolymer, e.g., in the range of 40-55 parts by weight, or in the range of 45-55 parts by weight, or in the range of 50-55 parts by weight.Embodiment 16. The polymer composition of any of embodiments 1-13, that is a reaction product of components comprising 35-50 parts by weight of the styrene / maleicanhydride copolymer, e.g., in the range of 40-50 parts by weight, or in the range of 45-50 parts by weight.Embodiment 17. The polymer composition of any of embodiments 1-13, that is a reaction product of components comprising 35-45 parts by weight of the styrene / maleic anhydride copolymer, e.g., in the range of 35-40 parts by weight, or in the range of 40-45 parts by weight.Embodiment 18. The polymer composition of any of embodiments 1-17, wherein the C8-C24hydrocarbyl primary amine component is a primary C8-C24 alkyl amine, a primary C8- C24 alkenyl amine, or a combination thereof.Embodiment 19. The polymer composition of any of embodiments 1-18, wherein the C8-C24hydrocarbyl primary amine component has a linear C8-C24 hydrocarbyl group.Embodiment 10. The polymer composition of any of embodiments 1-19, wherein at least 70 wt% of the C8-C24hydrocarbyl primary amine component has carbon chain lengths in the range of Ci0-C22, e.g., at least 80 wt%, or at least 90 wt%.Embodiment 21 . The polymer composition of any of embodiments 1-19, wherein at least 70 wt% of the C8-C24hydrocarbyl primary amine component has carbon chain lengths in the range of Ci4-C20, e.g., at least 80 wt%, or at least 90 wt%.Embodiment 22. The polymer composition of any of embodiments 1-19, wherein at least 70 wt% of the C8-C24hydrocarbyl primary amine component has carbon chain lengths in the range of Ci6-C20, e.g., at least 80 wt%, or at least 90 wt%.Embodiment 23. The polymer composition of any of embodiments 1-19, wherein at least 70 wt% of the C8-C24hydrocarbyl primary amine component has carbon chain lengths of Cis, e.g., at least 80 wt%, or at least 90 wt%.Embodiment 24. The polymer composition of any of embodiments 1-23, that is a reaction product of components comprising in the range of 32-60 parts by weight of the C8- C24 hydrocarbyl primary amine component, e.g., in the range of 35-60 parts by weight, or in the range 37-60 parts by weight, or in the range of 40-60 parts by weight, or in the range of 42-60 parts by weight, or in the range of 45-60 parts by weight, or in the range of 47-60 parts by weight, or in the range of 50-60 parts by weight, or in the range of 52-60 parts by weight.Embodiment 25. The polymer composition of any of embodiments 1-23, that is a reaction product of components comprising in the range of 30-57 parts by weight of the C8- C24 hydrocarbyl primary amine component, e.g., in the range of 32-57 parts by weight, or in the range of 35-57 parts by weight, or in the range of 40-57 parts by weight, or in the range of 42-57 parts by weight, or in the range of 45-57 parts by weight, or in the range of 47-57 parts by weight, or in the range of 50-57 parts by weight.Embodiment 26. The polymer composition of any of embodiments 1-23, that is a reaction product of components comprising in the range of 30-55 parts by weight of the C8- C24 hydrocarbyl primary amine component, e.g., in the range of 32-55 parts by weight, or in the range of 35-55 parts by weight, or in the range of 40-55 parts by weight, or in the range of 42-55 parts by weight, or in the range of 45-55 parts by weight, or in the range of 47-55 parts by weight, or in the range of 50-55 parts by weight.Embodiment 27. The polymer composition of any of embodiments 1-23, that is a reaction product of components comprising in the range of 30-52 parts by weight of the C8- C24 hydrocarbyl primary amine component, e.g., in the range of 32-52 parts by weight, or in the range of 35-52 parts by weight, or in the range of 40-52 parts by weight, or in the range of 42-52 parts by weight, or in the range of 45-52 parts by weight.Embodiment 28. The polymer composition of any of embodiments 1-27, wherein the polyethyleneimine oligomer component has a number-average degree of polymerization in the range of 2-8, e.g., in the range of 2-6, or 2-5, or 3-8, or 3-6, or 3-5.Embodiment 29. The polymer composition of any of embodiments 1-27, wherein the polyethyleneimine oligomer component has a number-average degree of polymerization in the range of 4-20, e.g., in the range of 4-15, or 4-10, or 4-8, or 7-20, or 7-15, or 7-10.Embodiment 30. The polymer composition of any of embodiments 1-29, wherein the polyethyleneimine oligomer is linear.Embodiment 31 . The polymer composition of any of embodiments 1-30, wherein the polyethyleneimine oligomer component is tetraethylenepentamine.Embodiment 32. The polymer composition of any of embodiments 1-31 , that is a reaction product of components comprising in the range of 0.5-4.5 parts by weight of thepolyethyleneimine component, e.g., in the range of 0.5-4.0 parts by weight, or in the range of 0.5-3.5 parts by weight, or in the range of 0.5-3.0 parts by weight, or in the range of 0.5-2.5 parts by weight, or in the range of 0.5-2.0 parts per weight.Embodiment 33. The polymer composition of any of embodiments 1-31 , that is a reaction product of components comprising in the range of 1 .0-5.0 parts by weight of the polyethyleneimine component, e.g., in the range of 1 .0-4.5 parts by weight, or in the range of 1 .0-4.0 parts by weight, or in the range of 1 .0-3.5 parts by weight, or in the range of 1 .0-3.0 parts by weight, or in the range of 1 .0-2.5 parts by weight, or in the range of 1 .0-2.0 parts by weight.Embodiment 34. The polymer composition of any of embodiments 1-31 , that is a reaction product of components comprising in the range of 1 .5-5.0 parts by weight of the polyethyleneimine component, e.g., in the range of 1 .5-4.5 parts by weight, or in the range of 1 .5-4.0 parts by weight, or in the range of 1 .5-3.5 parts by weight, or in the range of 1 .5-3.0 parts by weight, or in the range of 1 .5-2.5 parts by weight.Embodiment 35. The polymer composition of any of embodiments 1-34, wherein a molar ratio of the C8-C24 hydrocarbyl primary amine component to the polyethyleneimine oligomer component is at least 10:1 , e.g., at least 12:1 .Embodiment 36. The polymer composition of any of embodiments 1-34, wherein a molar ratio of the C8-C24 hydrocarbyl primary amine component to the polyethyleneimine oligomer component is at least 15:1 , e.g., at least 17:1 .Embodiment 37. The polymer composition of any of embodiments 1-34, wherein a molar ratio of the C8-C24hydrocarbyl primary amine component to the polyethyleneimine oligomer component is in the range of 10:1 to 30:1 , e.g., in the range of 10:1 to 25:1 , or in the range of 10:1 to 20:1 .Embodiment 38. The polymer composition of any of embodiments 1-34, wherein a molar ratio of the C8-C24hydrocarbyl primary amine component to the polyethyleneimine oligomer component is in the range of 12:1 to 30:1 , e.g., in the range of 12:1 to 25:1 , or in the range of 12:1 to 20:1 .Embodiment 39. The polymer composition of any of embodiments 1-34, wherein a molar ratio of the C8-C24 hydrocarbyl primary amine component to the polyethyleneimineoligomer component is in the range of 15:1 to 30:1 , e.g., in the range of 15:1 to 25:1 , or in the range of 15:1 to 20:1 .Embodiment 40. The polymer composition of any of embodiments 1-34, wherein a molar ratio of the C8-C24 hydrocarbyl primary amine component to the polyethyleneimine oligomer component is in the range of 17:1 to 30:1 , e.g., in the range of 17:1 to 25:1 , or in the range of 17:1 to 20:1 .Embodiment 41 . The polymer composition of any of embodiments 1-40, comprising C8- C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio of at least 10:1 , e.g., at least 12:1.Embodiment 42. The polymer composition of any of embodiments 1-40, comprising C8- C24 hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio of at least 15:1 , e.g., at least 17:1.Embodiment 43. The polymer composition of any of embodiments 1-40, comprising C8- C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio in the range of 10:1 to 30:1 , e.g., in the range of 10:1 to 25:1 , or in the range of 10:1 to 20:1.Embodiment 44. The polymer composition of any of embodiments 1-40, comprising C8- C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio in the range of 12:1 to 30:1 , e.g., in the range of 12:1 to 25:1 , or in the range of 12:1 to 20:1.Embodiment 45. The polymer composition of any of embodiments 1-40, comprising C8- C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio in the range of 15:1 to 30:1 , e.g., in the range of 15:1 to 25:1 , or in the range of 15:1 to 20:1.Embodiment 46. The polymer composition of any of embodiments 1-40, comprising C8- C24hydrocarbyl primary amine residues and polyethyleneimine oligomer residues in a molar ratio in the range of 17:1 to 30:1 , e.g., in the range of 17:1 to 25:1 , or in the range of 17:1 to 20:1.Embodiment 47. The polymer composition of any of embodiments 1-46, wherein the total amount of styrene residues, maleic anhydride residues, C8-C24 hydrocarbyl primary amine residues, and polyethyleneimine oligomer residues is at least 85 wt% of the total weight of the polymer composition, e.g., at least 90 wt%.Embodiment 48. The polymer composition of any of embodiments 1-46, wherein the total amount of styrene residues, maleic anhydride residues, C8-C24 hydrocarbyl primary amine residues, and polyethyleneimine oligomer residues is at least 95 wt% of the total weight of the polymer composition, e.g., at least 98 wt%.Embodiment 49. The polymer composition of any of embodiments 1-48, wherein a weight-average molecular weight of the polymer composition is in the range of 15-50 kDa, e.g., in the range of 15-45 kDa, or in the range of 15-40 kDa, or in the range of 20-50 kDa, or in the range of 20-45 kDa, or in the range of 20-40 kDa, as determined by gel permeation chromatography.Embodiment 50. The polymer composition of any of embodiments 1-48, wherein a weight-average molecular weight of the polymer composition is in the range of 25-50 kDa, or in the range of 25-45 kDa, or in the range of 25-40 kDa, or in the range of 30-50 kDa, or in the range of 30-45 kDa, or in the range of 30-40 kDa, as determined by gel permeation chromatography.Embodiment 51 . The polymer composition of any of embodiments 1-50, wherein the polymer composition has an acid value of no more than 20 mg KOH / g, e.g., no more than 18 mg KOH / g, or no more than 16 mg KOH / g, or no more than 14 mg KOH / g, or no more than 12 mg KOH / g, or no more than 10 mg KOH / g.Embodiment 52. The polymer composition of embodiment 51 , wherein the acid value is no more than 5% of an acid value of the styrene / maleic anhydride copolymer, e.g., no more than 4%, or no more than 3%, or no more than 2%.Embodiment 53. The polymer composition of any of embodiments 1-52, dispersed in an aromatic hydrocarbon solvent having an atmospheric boiling point in the range of 120-180 °C.Embodiment 54. The polymer composition of any of embodiments 1-52, having no more than 3 wt% of solvents having an atmospheric pressure boiling point less than 180 °C,e.g., no more than 2 wt%, or no more than 1 wt%, based on the total weight of the polymer composition.Embodiment 55. The polymer composition of any of embodiments 1-52, having no more than 3 wt% of solvents having an atmospheric pressure boiling point in the range of 120-180 °C, e.g., no more than 2 wt%, or no more than 1 wt%, based on the total weight of the polymer composition.Embodiment 56. A lubricant comprising: a base oil, and a polymer composition according to any of embodiments 1-55, present in an amount in the range of 0.1-5 wt% of a total weight of the lubricant, as determined on a solids basis.Embodiment 57. The lubricant of embodiment 56, wherein the base oil comprises (or is) a Group II base oil and / or a Group III base oil.Embodiment 58. The lubricant of embodiment 56, wherein the base oil comprises (or is) a Group III base oil.Embodiment 59. The lubricant of any of embodiments 56-58, having a total amount of Group II base oil and Group III base oil in the range of 40-90 wt% of the total weight of the lubricant, e.g., in the range of 40-85 wt%, or in the range of 40-80 wt%, or in the range of 40- 70 wt%, or in the range of 50-90 wt%, or in the range of 50-85 wt%, or in the range of 50-80 wt%, or in the range of 50-80 wt%, or in the range of 50-70 wt%.Embodiment 60. The lubricant of any of embodiments 56-58, having a total amount of Group II base oil and Group III base oil of at least 80 wt% of the total weight of the lubricant, e.g., in the range of 80-90 wt%, or in the range of 80-85 wt%.Embodiment 61 . The lubricant of any of embodiments 56-58, having a total amount of Group II base oil and Group III base oil of at least 85 wt% of the total weight of the lubricant, e.g., in the range of 85-90 wt%.Embodiment 62. The lubricant of any of embodiments 56-61 , wherein a Group IV base oil is present in an amount of no more than 10 wt% of the total weight of the lubricant, e.g., no more than 5 wt%, or no more than 2 wt%, or no more than 1 wt%.Embodiment 63. The lubricant of any of embodiments 56-61 , wherein substantially no Group IV base oil is present.Embodiment 64. The lubricant of any of embodiments 56-61 , further wherein the base oil comprises a Group IV base oil in an amount in the range of 10-30 wt% of the total weight of the lubricant, e.g., in the range of 15-25 wt%.Embodiment 65. The lubricant of embodiment 64, wherein the Group IV base oil is a polyalphaolefin.Embodiment 66. The lubricant of any of embodiments 56-63, having a total amount of base oil in the range of 40-90 wt% of the total weight of the lubricant, e.g., in the range of 40- 85 wt%, or in the range of 40-80 wt%, or in the range of 40-70 wt%, or in the range of 50-90 wt%, or in the range of 50-85 wt%, or in the range of 50-80 wt%, or in the range of 50-70 wt%.Embodiment 67. The lubricant of any of embodiments 56-58, having a total amount of base oil of at least 80 wt% of the total weight of the lubricant, e.g., in the range of 80-90 wt%, or in the range of 80-85 wt%.Embodiment 68. The lubricant of any of embodiments 56-58, having a total amount of base oil of at least 85 wt% of the total weight of the lubricant, e.g., in the range of 85-90 wt%.Embodiment 69. The lubricant of any of embodiments 56-68, wherein the polymer composition is present in an amount in the range of 0.1 -4.5 wt% of the total weight of the lubricant, e.g., in the range of 0.1-4.0 wt%, or in the range of 0.1-3.5 wt%, or in the range of 0.1-3.0 wt%, or in the range of 0.1-2.5 wt%, or in the range of 0.1-2.0 wt%, or in the range of 0.1-1 .5 wt%.Embodiment 70. The lubricant of any of embodiments 56-68, wherein the polymer composition is present in an amount in the range of 0.3-5.0 wt% of the total weight of the lubricant, e.g., in the range of 0.3-4.5 wt%, or in the range of 0.3-4.0 wt%, or in the range of 0.3-3.5 wt%, or in the range of 0.3-3.0 wt%, or in the range of 0.3-2.5 wt%, or in the range of 0.3-2.0 wt%, or in the range of 0.3-1 .5 wt%.Embodiment 71 . The lubricant of any of embodiments 56-68, wherein the polymer composition is present in an amount in the range of 0.5-5.0 wt% of the total weight of the lubricant, e.g., in the range of 0.5-4.5 wt%, or in the range of 0.5-4.0 wt%, or in the range of 0.5-3.5 wt%, or in the range of 0.5-3.0 wt%, or in the range of 0.5-2.5 wt%, or in the range of 0.5-2.0 wt%, or in the range of 0.5-1 .5 wt%.Embodiment 72. The lubricant of any of embodiments 56-68, wherein the polymer composition is present in an amount in the range of 0.7-5.0 wt% of the total weight of the lubricant, e.g., in the range of 0.7-4.5 wt%, or in the range of 0.7-4.0 wt%, or in the range of 0.7-3.5 wt%, or in the range of 0.7-3.0 wt%, or in the range of 0.7-2.5 wt%, or in the range of 0.7-2.0 wt%, or in the range of 0.7-1 .5 wt%.Embodiment 73. The lubricant of any of embodiments 56-72, further comprising one or more dispersants, present in an amount up to 20 wt% of the total weight of the lubricant, e.g., up to 15 wt%, or up to 10 wt%, or in the range of 1-20 wt%, or 1-15 wt%, or 1-10 wt%, or 2-20 wt%, or 2-10 wt%, or 2-15 wt%, or 3-20 wt%, or 3-15 wt%, or 3-12 wt%, or 3-10 wt%, or 5-20 wt%, or 5-15 wt%, or 5-12 wt%, or 5-10 wt%.Embodiment 74. The lubricant of any of embodiments 56-73, having a kinematic viscosity at 100 °C of no more than 10 cSt, e.g., no more than 9 cSt, or no more than 8 cSt, or no more than 7 cSt.Embodiment 75. The lubricant of any of embodiments 56-73, having a kinematic viscosity at 100 °C in the range of 4-10 cSt, e.g., in the range of 4-8 cSt, or in the range of 5- 9 cSt, or in the range of 5-7 cSt.Embodiment 76. The lubricant of any of embodiments 56-73, having a kinematic viscosity at 40 °C of no more than 40 cSt, e.g., no more than 38 cSt, or no more than 35 cSt, or no more than 32 cSt, or no more than 30 cSt, or no more than 28 cSt.Embodiment 77. The lubricant of any of embodiments 56-73, having a kinematic viscosity at 40 °C in the range of 18-40 cSt, e.g., in the range of 18-35 cSt, or in the range of 18-30 cSt, or in the range of 18-28 cSt, or in the range of 20-40 cSt, or in the range of 20-35 cSt, or in the range of 20-30 cSt, or in the range of 25-40 cSt, or in the range of 25-35 cSt, or in the range of 25-30 cSt.Embodiment 78. The lubricant of any of embodiments 56-77, having a kinematic viscosity at 20 °C of no more than 80 cSt, e.g., no more than 78 cSt, or no more than 75 cSt, or no more than 73 cSt, or no more than 70 cSt, or no more than 68 cSt.Embodiment 79. The lubricant of any of embodiments 56-77, having a kinematic viscosity at 20 °C in the range of 40-80 cSt, e.g., in the range of 40-75 cSt, or in the range of 40-70 cSt, or in the range of 45-80 cSt, or in the range of 45-75 cSt, or in the range of 45-70 cSt, or in the range of 50-80 cSt or in the range of 50-75 cSt, or in the range of 50-70 cSt.Embodiment 80. The lubricant of any of embodiments 56-79, comprising no more than2.5 wt%, e.g., no more than 2.4 wt%, or no more than 2.3 wt%, or no more than 2.2 wt%, or no more than 2.1 wt%, or no more than 2.0 wt%, of anti-oxidants.Embodiment 81 . The lubricant of any of embodiments 56-80, comprising no more than1 .5 wt%, e.g., no more than 1 .4 wt%, or no more than 1 .3 wt%, or no more than 1 .2 wt%, or no more than 1 .1 wt%, or no more than 1 .0 wt%, of aminic anti-oxidants.Embodiment 82. The lubricant of any of embodiments 56-72 or 73-81 , comprising no more than 6.5 wt%, e.g., no more than 6.4 wt%, or no more than 6.3 wt%, or no more than 6.2 wt%, or no more than 6.1 wt%, or no more than 6.0 wt%, of additional dispersants.Embodiment 83. The lubricant of any of embodiments 56-72 or 73-82, comprising no more than 2.2 wt%, e.g., no more than 2.1 wt%, or no more than 2.0 wt%, or no more than 1 .9 wt%, or no more than 1 .8 wt%, or no more than 1 .7 wt%, of a non-borated dispersant.Embodiment 84. The lubricant of any of embodiments 56-72 or 73-83, comprising no more than 3.4 wt%, e.g., no more than 3.2 wt%, or no more than 3.0 wt%, or no more than 2.8 wt%, of a high molecular weight dispersant.Embodiment 85. The lubricant of any of embodiments 56-84, comprising no more than 0.6 wt%, e.g., no more than 0.5 wt%, or no more than 0.4 wt%, or no more than 0.3 wt%, or no more than 0.2 wt%, or no more than 0.1 wt%, or no more than 0.05 wt% of corrosion inhibitors.Embodiment 86. The lubricant of any of embodiments 56-85, comprising no more than 15 wt%, e.g., no more than 14 wt%, or no more than 13 wt%, or no more than 12 wt%, of non-polymeric additives.Embodiment 87. The lubricant of any of embodiments 56-86, wherein the lubricant is disposed inside an internal combustion engine.Embodiment 88. The lubricant of any of embodiments 56-87, wherein the lubricant exhibits at least as good a copper string rating as an otherwise identical lubricant when subjected to a HTCBT, as determined by ASTM D6594.Embodiment 89. The lubricant of any of embodiments 56-88, wherein the lubricant exhibits a copper string rating of no worse than “3a” when subjected to a HTCBT, as determined by ASTM D6594.Embodiment 90. The lubricant of any of embodiments 56-88, wherein the lubricant exhibits a copper string rating of “3a” when subjected to a HTCBT, as determined by ASTM D6594.Embodiment 91 . The lubricant of any of embodiments 56-90, wherein the lubricant exhibits a change in Sn concentration of no more than 10 mg / kg, e.g., no more than 5 mg / kg, or no more than 2 mg / kg, or no more than 1 mg / kg, or no more than 0.5 mg / kg, when subjected to a HTCBT, as determined by ASTM D6594.Embodiment 92. The lubricant of embodiment 91 , wherein the change in Sn concentration is no more than 120% of a change in Sn concentration exhibited by an otherwise identical lubricant lacking the polymer composition when subjected to a HTCBT, e.g., no more than 115%, or no more than 110%, or no more than 105%, as determined by ASTM D6594.Embodiment 93. The lubricant of embodiment 91 , wherein the change in Sn concentration is in the range of 80-120% of a change in Sn concentration exhibited by an otherwise identical lubricant lacking the polymer composition when subjected to a HTCBT, e.g., in the range of 85-115%, or in the range of 90-110%, or in the range of 95-105%, as determined by ASTM D6594.Embodiment 94. The lubricant of any of embodiments 56-93, wherein the lubricant exhibits a change in Pb concentration of no more than 50 mg / kg when subjected to a HTCBT, e.g., no more than 40 mg / kg, or no more than 30 mg / kg, or no more than 20 mg / kg, or no more than 10 mg / kg, or no more than 5 mg / kg, as determined by ASTM D6594.Embodiment 95. The lubricant of any of embodiments 56-93, wherein the lubricant exhibits a change in Pb concentration in the range of 0.01-10 mg / kg when subjected to a HTCBT, e.g., in the range of 0.05-10 mg / kg, or in the range of 0.1-10 mg / kg, or in the range of 0.5-10 mg / kg, or in the range of 1-10 mg / kg, or in the range of 0.01-5 mg / kg, or in the range of 0.05-5 mg / kg, or in the range of 0.1-5 mg / kg, or in the range of 0.5-5 mg / kg, or in the range of 1-5 mg / kg, or in the range of 0.01-3 mg / kg, or in the range of 0.05-3 mg / kg, or in the range of 0.1-3 mg / kg, or in the range of 1-3 kg as determined by ASTM D6594.Embodiment 96. The lubricant of embodiment 94 or embodiment 95, wherein the change in Pb concentration is no more than 50% of a change in Pb concentration exhibited by an otherwise identical lubricant lacking the polymer composition when subjected to a HTCBT, e.g., no more than 40%, or no more than 30%, or no more than 25%, or no more than 20%, or no more than 15%, or no more than 10%, or no more than 5%, as determined by ASTM D6594.Embodiment 97. The lubricant of any of embodiments 56-96, wherein the lubricant exhibits a change in Cu concentration of no more than 80 ppm when subjected to a HTCBT, e.g., no more than 70 ppm, or no more than 60 ppm, or no more than 50 ppm, or no more than 45 ppm, or no more than 40 ppm, as determined by ASTM D6594.Embodiment 98. The lubricant of any of embodiments 56-96, wherein the lubricant exhibits a change in Cu concentration in the range of 5-50 ppm when subjected to a HTCBT, e.g., in the range of 5-45 ppm, or in the range of 5-40 ppm, or in the range of 10-50 ppm, or in the range of 10-45 ppm, or in the range of 10-40 ppm, or in the range of 15-50 ppm, or in the range of 15-45 ppm, or in the range of 15-40 ppm, as determined by ASTM D6594.Embodiment 99. The lubricant of embodiment 97 or embodiment 98, wherein the change in Cu concentration is no more than 80% of a change in Cu concentration exhibited by an otherwise identical lubricant lacking the polymer composition when subjected to a HTCBT, e.g., no more than 70%, or no more than 60%, or no more than 55%, or no more than 50%, or no more than 45%, or no more than 40%, as determined by ASTM D6594.Embodiment 100. The lubricant of any of embodiments 56-99, wherein the lubricant meets the requirements for a 0W-20 oil.Embodiment 101 . The lubricant of any of embodiments 56-99, wherein the lubricant meets the requirements for a OW-16 oil.Embodiment 102. The lubricant of any of embodiments 56-99, wherein the lubricant meets the requirements for a OW-12 oil.Embodiment 103. The lubricant of any of embodiments 56-99, wherein the lubricant meets the requirements for a OW-8 oil.Embodiment 104. The use of a lubricant according to any of embodiments 56-103 in the lubrication of an internal combustion engine.Embodiment 105. A method for lubricating an internal combustion engine, the method providing supplying a lubricant according to any of embodiments 56-103 to the internal combustion engine, and operating the internal combustion engine with the lubricant supplied thereto.Embodiment 106. The use or method of claim 104 or claim 105, wherein the internal combustion engine is an engine of a vehicle, e.g., a car, a truck, or a motorcycle.

[0081] The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of various embodiments of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention, the description taken with the drawings and / or examples making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. Thus, before the disclosed processes and devices are described, it is to be understood that the aspects described herein are not limited to specific embodiments, apparatuses, or configurations, and as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and, unless specifically defined herein, is not intended to be limiting.

[0082] The terms “a,” “an,” “the” and similar referents used in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0083] All methods described herein can be performed in any suitable order of steps unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0084] Unless the context clearly requires otherwise, throughout the description and the claims, the words ‘comprise’, ‘comprising’, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”. Words using the singular or plural number also include the plural and singular number, respectively. Additionally, the words “herein,” “above,” and “below” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of the application.

[0085] As will be understood by one of ordinary skill in the art, each embodiment disclosed herein can comprise, consist essentially of or consist of its particular stated element, step, ingredient or component. As used herein, the transition term “comprise” or “comprises” means includes, but is not limited to, and allows for the inclusion of unspecified elements, steps, ingredients, or components, even in major amounts. The transitional phrase “consisting of’ excludes any element, step, ingredient or component not specified. The transition phrase “consisting essentially of’ limits the scope of the embodiment to the specified elements, steps, ingredients or components and to those that do not materially affect the embodiment.

[0086] Unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0087] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0088] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and / or patentability. When any such inclusion or deletion occurs, the specification is deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

[0089] Some embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

[0090] Furthermore, it is to be understood that the embodiments of the invention disclosed herein are illustrative of the principles of the present invention. Other modifications that may be employed are within the scope of the invention. Thus, by way of example, but not of limitation, alternative configurations of the present invention may be utilized in accordance with the teachings herein. Accordingly, the present invention is not limited to that precisely as shown and described.

Claims

We claim:1 . A polymer composition that is a reaction product of components comprising: 35-60 parts by weight of a styrene / maleic anhydride copolymer, wherein the styrene / maleic anhydride copolymer comprises: 40-80 wt% styrene residues, and 20-60 wt% maleic anhydride residues, each based on a total weight of the styrene / maleic anhydride copolymer, at least 80 wt% of the styrene / maleic anhydride copolymer being formed of residues of styrene and maleic anhydride;30-60 parts by weight of a C8-C24 hydrocarbyl primary amine component; and0.5-5 parts by weight of a polyethyleneimine oligomer component, wherein a total amount of styrene residues, maleic anhydride residues, C8-C24 hydrocarbyl primary amine residues and polyethyleneimine oligomer residues is at least 80 wt% of the polymer composition.

2. The polymer composition of claim 1 , wherein a molar ratio of the C8-C24 hydrocarbyl primary amine component to the polyethyleneimine oligomer component is at least 10:1.

3. The polymer composition of claim 1 , wherein the styrene / maleic anhydride copolymer comprises in the range of 40-60 wt% styrene residues, and in the range of 40-60 wt% maleic anhydride residues, based on the total weight of the styrene / maleic anhydride copolymer .

4. The polymer composition claim 1 , wherein at least 95 wt% of the total weight of the styrene / maleic anhydride copolymer is formed of styrene and maleic anhydride residues.

5. The polymer composition of claim 1 , wherein the styrene / maleic anhydride copolymer has a weight-average molecular weight in the range of 2,000 to 10,000 g / mol, as determined by gel permeation chromatography.

6. The polymer composition of claim 1 , wherein at least 80 wt% of the C8-C24hydrocarbyl primary amine component is alkyl primary amine having carbon chain lengths in the range of Ci6-C20.

7. The polymer composition of claim 1 , wherein the polyethyleneimine oligomer component has a number-average degree of polymerization in the range of 3-8.

8. The polymer composition of claim 1 , wherein the total amount of styrene residues, maleic anhydride residues, C8-C24 hydrocarbyl primary amine residues, and polyethyleneimine oligomer residues is in the range of 95 wt%.

9. The polymer composition of claim 1 , wherein a weight-average molecular weight of the polymer composition is in the range of 15-50 kDa, as determined by gel permeation chromatography.

10. A lubricant comprising: a base oil, and a polymer composition according to any of claims 1-9, present in an amount in the range of 0.1-5 wt% of a total weight of the lubricant, as determined on a solids basis.

11. The lubricant of claim 10, wherein the base oil comprises a Group II base oil and / or a Group III base oil, and wherein a Group IV base oil is present in an amount of no more than 10 wt% of the total weight of the lubricant.

12. The lubricant of claim 10, wherein the polymer composition is present in an amount in the range of 0.3-3.0 wt% of the total weight of the lubricant.

13. The lubricant of claim 10, having a kinematic viscosity at 100 °C of no more than 8 cSt, and a kinematic viscosity at 40 °C of no more than 35 cSt.

14. The lubricant claim 10, wherein the lubricant meets the requirements for a 0W-20 oil, a OW-16 oil, a OW-12 oil, or a OW-8 oil.

15. Use of a lubricant of any of claims 1-9 in the lubrication of an internal combustion engine.

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