Abstract: Chlorine-free polyfunctional polyisobutenes are described that can be modified by amines, alcohols and/or amino alcohols to result in additives that can be used in the petroleum field in particular in fuels and engine lubricants.They are prepared by radical terpolymerization of isobutene, maleic anhydride and polyisobutene having an average content of "exo" end double bonds of at least 50%.

Abstract: Additive formulation for engine fuels incorporating at least one constituent (A) and at least one constituent (B), constituent(A) consisting of at least one composition incorporating products resulting from the reaction of at least one dicarboxylic compound(D), whose carboxylic functions are separated by at the most eight carbon atoms, with at least one polyoxyalkylene glycol or glycol mono-ether (E) of general formula (I):R.sup.1 --O--(R.sup.2 --O).sub.n --H,in which R.sup.1 represents a hydrocarbon group having 1 to 30 carbon atoms, R.sup.2 represents a divalent hydrocarbon group having 2 to 6 carbon atoms and n is a number from 1 to 60; and constituent (B) consisting of at least one detergent-dispersant product. This formulation preferably also comprises a constituent (C) chosen from within the group formed by mineral or synthetic lubricating oils and polyglycols soluble in the fuel.

Abstract: Polynitrogen compound having two terminal cycles of the imide type, its preparation by conventional organic chemistry methods and its use as an additive for engine fuel. This compound complies with the general formula (I): ##STR1## in which R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are as set forth in the specification.