The multipurpose additives of the invention are the reaction products of (a) a glycidyl ether compound (I) of the formula: ##STR1## where R6 is an aliphatic hydrocarbon group containing at least 8 carbon atoms and m is 1-3, and (b) a primary or secondary monoamine or polyamine, that is, an amine having at least one amino group having at least one active hydrogen atom.