Novel copolymer and use thereof as a fuel additive

A copolymer comprising:

• at least one unit of formula (I) below:
• in which
• u=0 or 1,
• R1′ represents a hydrogen atom or a methyl group,
• E represents —O— or —N(Z)—, or —O—CO—, or —CO— or —NH—CO— or —CO—NH—, with Z representing H or a C1 to C6 alkyl group,
• G represents a group chosen from a C1 to C34 alkyl group, an aromatic nucleus, an aralkyl group comprising at least one aromatic nucleus and at least one C1 to C34 alkyl group, and
• units of formula (II) below:
• in which
• v=0 or 1,
• R1″ is chosen from a hydrogen atom and a methyl group,
• Q is chosen from an oxygen atom and a group —NR′— with R′ being chosen from a hydrogen atom and C1 to C12 hydrocarbon-based chains,
• R represents a C1 to C34 hydrocarbon-based chain which may also contain one or more nitrogen and/or oxygen atoms and/or carbonyl groups, substituted with at least one non-quaternary amine group and/or at least one quaternary amine group,
• said non-quaternary amine group comprising at least one primary, secondary or tertiary amine function,
• said quaternary amine group comprising at least one quaternary ammonium function and optionally one or more hydroxyl groups,
• 5 mol % to 95 mol % of the groups R of the units of formula (II) comprising at least one quaternary amine group.