The present invention concerns the use, for lowering the cold filter plugging point of a fuel composition, of one or more crosslinked polymers comprising at least one unit of the following formula (I): in which R.sub.1 represents a hydrogen atom or a methyl group; E represents —O—CO—, or —CO—O— or —NH—CO— or —CO—NH—; and G represents a C.sub.1 to C.sub.34 alkyl group; said copolymer having a crosslinking rate of between 0.5 mol % and 30 mol %. The invention also concerns additive compositions containing such a polymer, and fuel compositions with such polymers as additives, in combination with a cold flow improver (CFI) chosen from the copolymers and terpolymers of ethylene and vinyl and/or acrylic ester(s).

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The invention relates to a composition of additives for fuel, comprising: (a) one or more copolymer(s) comprising the following units of formulae (I) and units of formula (IIa): R representing a hydrocarbon-based chain substituted with at least one amino group comprising at least one quaternary ammonium or iminium function, and (b) one or more copolymer(s) comprising units of formulae (I) and units of formula (IIb): R representing a hydrocarbon-based chain substituted with at least one amino group comprising at least one primary, secondary or tertiary amine function or imine function. The invention also relates to the use of such a composition as a detergent additive and/or demulsifying additive in a liquid fuel for an internal combustion engine.

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Described herein are associative polymers capable of controlling one or more physical and/or chemical properties of non-polar compositions and related compositions, methods and systems.

The present disclosure provides a poly(vinyl caprolactam) polymer obtained by polymerizing a vinyl lactam compound in a polymerization solvent system comprising an alkylene carbonate and/or an alkyl lactate and a polymerization initiator. The poly(vinyl caprolactam) polymer, in admixture with the polymerization solvent system, may be used as a kinetic gas hydrate inhibitor to prevent or inhibit formation of natural gas and/or liquid hydrocarbon hydrates in a system.

Described herein are associative polymers capable of controlling a physical and/or chemical property of non-polar compositions that can be used when the non-polar composition is in a flow, and related compositions, methods and systems. Associative polymers herein described have a non-polar backbone with a longest span having a molecular weight that remains substantially unchanged under the flow conditions and functional groups presented at ends of the non-polar backbone, with a number of the functional groups presented at the ends of the non-polar backbone formed by associative functional groups capable of undergoing an associative interaction with another associative functional group with an association constant (k) such that the strength of each associative interaction is less than the strength of a covalent bond between atoms and in particular less than the strength of a covalent bond between backbone atoms.

Provided is a composition comprising at least one polymer, the repeat unit of which comprises at least one amide functional group, at least one polyetheramine with a weight-average molecular weight (M.sub.W) of greater than 100 g.mol.sup.1 and exhibiting at least two secondary and/or tertiary amine functional groups, and optionally, but preferably, at least one organic solvent. Also provided is method of using of the composition for delaying, indeed even preventing, the formation of gas hydrates, in particular in a process for extracting oil and/or gas and/or condensates, and also to the process for delaying, indeed even preventing, the formation and/or the agglomeration of gas hydrates, employing a composition as defined above.

Provided is a composition comprising at least one polymer, the repeat unit of which comprises at least one amide functional group, at least one polyetheramine with a weight-average molecular weight (M.sub.W) of greater than 100 g.mol.sup.1 and exhibiting at least two secondary and/or tertiary amine functional groups, and optionally, but preferably, at least one organic solvent. Also provided is method of using of the composition for delaying, indeed even preventing, the formation of gas hydrates, in particular in a process for extracting oil and/or gas and/or condensates, and also to the process for delaying, indeed even preventing, the formation and/or the agglomeration of gas hydrates, employing a composition as defined above.

Described herein are associative polymers capable of controlling a physical and/or chemical property of non-polar compositions that can be used when the non-polar composition is in a flow, and related compositions, methods and systems. Associative polymers herein described have a non-polar backbone with a longest span having a molecular weight that remains substantially unchanged under the flow conditions and functional groups presented at ends of the non-polar backbone, with a number of the functional groups presented at the ends of the non-polar backbone formed by associative functional groups capable of undergoing an associative interaction with another associative functional group with an association constant (k) such that the strength of each associative interaction is less than the strength of a covalent bond between atoms and in particular less than the strength of a covalent bond between backbone atoms.

Described herein are associative polymers capable of controlling one or more physical and/or chemical properties of non-polar compositions and related compositions, methods and systems.

The present disclosure provides a poly(vinyl caprolactam) polymer obtained by polymerizing a vinyl lactam compound in a polymerization solvent system comprising an alkylene carbonate and/or an alkyl lactate and a polymerization initiator. The poly(vinyl caprolactam) polymer, in admixture with the polymerization solvent system, may be used as a kinetic gas hydrate inhibitor to prevent or inhibit formation of natural gas and/or liquid hydrocarbon hydrates in a system.