Fuel compositions containing improved branched amido-amine dispersant additives

A fuel composition containing a dispersant additive formed by a process which comprises:

• (a) contacting in a first liquid reaction mixture a first nitrogen-containing compound having at least two reactive nitrogen moieties with a polyfunctional reactant having within its structure a first functional group reactive with a --NH-- group, and at least one additional functional group reactive with a --NH-- group, in an amount and under conditions sufficient to selectively react at least a portion of the first functional groups in the polyfunctional reactant with the reactive nitrogen moieties to form a first adduct;
• (b) contacting the first adduct with a second nitrogen-containing compound having at least two --NH-- groups in an amount and under conditions sufficient to react the additional functional groups in the first adduct with the --NH-- groups in the second nitrogen-containing compound to form a second adduct characterized by having within its structure on average (i) at least two nitrogen-containing moieties derived from the second nitrogen-containing compound per nitrogen-containing moiety derived from the first nitrogen-containing compound and (ii) at least two unreacted primary or secondary amine groups per molecule;
• and
• (c) contacting the second adduct in a second liquid reaction mixture with at least one long chain hydrocarbon substituted with mono- or dicarboxylic acid, anhydride or ester groups;
• wherein the polyfunctional reactant comprises at least one alpha, beta-unsaturated compound of the formula:
• ##STR47## wherein X is sulfur or oxygen, Y is --OR.sup.4, --SR.sup.4, or --NR.sup.4 (R.sup.5), and R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are the same or different and are hydrogen or substituted or unsubstituted hydrocarbyl.