Compositions resulting from the mixing of at least one oligomer A1, resulting from the copolymerization of at least one monomer functionalized by diol functions with at least a second monomer, and at least one compound A2 including at least two boronic ester functions. The compositions exhibit very varied rheological properties, depending on the proportion of the compounds A1 and A2 used. A composition also results from mixing at least one lubricating oil with such a composition of associative and exchangeable polymers, and to the use of this composition to lubricate a mechanical part.

A crankcase lubricating oil composition for the crankcase of a spark-ignited or compression-ignited internal combustion engine, comprising a magnesium-containing detergent, in an amount sufficient to provide from 200-4000 ppm magnesium to the lubricating oil composition, in combination with an oil-soluble or oil-dispersible molybdenum compound in an amount sufficient to provide from 600-1500 ppm molybdenum atoms to the lubricating oil composition, and with an oil-soluble or oil-dispersible boron-containing compound in an amount sufficient to provide from 200-600 ppm boron atoms to the lubricating oil composition to improve the friction and fuel economy performance.

A crankcase lubricating oil composition for the crankcase of a spark-ignited or compression-ignited internal combustion engine, comprising a magnesium-containing detergent, in an amount sufficient to provide from 200-4000 ppm magnesium to the lubricating oil composition, in combination with an oil-soluble or oil-dispersible molybdenum compound in an amount sufficient to provide from 600-1500 ppm molybdenum atoms to the lubricating oil composition, and with an oil-soluble or oil-dispersible boron-containing compound in an amount sufficient to provide from 200-600 ppm boron atoms to the lubricating oil composition to improve the friction and fuel economy performance.

Compositions are obtained by mixing at least one oligomer A1, which is obtained by copolymerizing at least two monomers functionalized by diol functions with at least one second monomer, with at least one compound A2 having at least two boron ester functions. The compositions exhibit very varied rheological properties depending on the proportion of the compounds A1 and A2 used. A composition is also obtained by mixing at least one lubricating oil with such a composition of associative and exchangeable polymers, and the use of this composition to lubricate a mechanical part.

A crankcase lubricating oil composition for the crankcase of a spark-ignited or compression-ignited internal combustion engine, comprising a magnesium-containing detergent, in an amount sufficient to provide from 200-4000 ppm magnesium to the lubricating oil composition, in combination with an oil-soluble or oil-dispersible molybdenum compound in an amount sufficient to provide from 600-1500 ppm molybdenum atoms to the lubricating oil composition, and with an oil-soluble or oil-dispersible boron-containing compound in an amount sufficient to provide from 200-600 ppm boron atoms to the lubricating oil composition to improve the friction and fuel economy performance.

A crankcase lubricating oil composition for the crankcase of a spark-ignited or compression-ignited internal combustion engine, comprising a magnesium-containing detergent, in an amount sufficient to provide from 200-4000 ppm magnesium to the lubricating oil composition, in combination with an oil-soluble or oil-dispersible molybdenum compound in an amount sufficient to provide from 600-1500 ppm molybdenum atoms to the lubricating oil composition, and with an oil-soluble or oil-dispersible boron-containing compound in an amount sufficient to provide from 200-600 ppm boron atoms to the lubricating oil composition to improve the friction and fuel economy performance.

A composition is obtained by mixing at least one oligomer A1, which is obtained by copolymerizing at least two monomers functionalized by diol functions with at least one second monomer, with at least one compound A2 having at least two boron ester functions. The compositions exhibit very varied rheological properties depending on the proportion of the compounds A1 and A2 used. A composition is also obtained by mixing at least one lubricating oil with such a composition of associative and exchangeable polymers, and the use of this composition to lubricate a mechanical part.

A composition is obtained by mixing at least one oligomer A1, which is obtained by copolymerizing at least two monomers functionalized by diol functions with at least one second monomer, with at least one compound A2 having at least two boron ester functions. The compositions exhibit very varied rheological properties depending on the proportion of the compounds A1 and A2 used. A composition is also obtained by mixing at least one lubricating oil with such a composition of associative and exchangeable polymers, and the use of this composition to lubricate a mechanical part.

Compositions resulting from the mixing of at least: a comb polydiol copolymer A1 and a compound A2 including at least two boronic ester functional groups, the comb polydiol copolymer A1 including a main chain and side chains, at least a portion of the side chains of the copolymer A1 being composed of oligomers. They exhibit very varied rheological properties depending on the proportion of the compounds A1 and A2 used. Composition resulting from the mixing of at least one lubricating oil with such a composition of associative and exchangeable polymers and use of this composition for lubricating a mechanical part.

Compositions resulting from the mixing of at least: a comb polydiol copolymer A1 and a compound A2 including at least two boronic ester functional groups, the comb polydiol copolymer A1 including a main chain and side chains, at least a portion of the side chains of the copolymer A1 being composed of oligomers. They exhibit very varied rheological properties depending on the proportion of the compounds A1 and A2 used. Composition resulting from the mixing of at least one lubricating oil with such a composition of associative and exchangeable polymers and use of this composition for lubricating a mechanical part.