Block or graft copolymers and their use as surfactants

A copolymer suitable for use as a surfactant in a system consisting of an oil phase and an aqueous phase, the copolymer containing at least two polymeric components which are derived from oil-soluble complex monocarboxylic acids and another polymeric component which is the residue of a water-soluble compound containing polyoxyalkylene chains, characterized in that the copolymer has the general formula (A--COO).sub.m --B, wherein m is an integer at least 2, wherein each polymeric component A has a molecular weight of at least 500 and is the residue of an oil-soluble complex monocarboxylic acid having the general structural formula ##STR7## in which R is hydrogen or a monovalent hydrocarbon or substituted hydrocarbon group;

• R.sub.1 is hydrogen or a monovalent C.sub.1 to C.sub.24 hydrocarbon group;
• R.sub.2 is a divalent C.sub.1 to C.sub.24 hydrocarbon group;
• n is zero or 1;
• p is an integer from zero up to 200;
• and wherein each polymeric component B has a molecular weight of at least 500 and, in the case where m is 2, is the divalent residue of a water-soluble polyalkylene glycol having the general formula ##STR8## in which R.sub.3 is hydrogen or a C.sub.1 or C.sub.3 alkyl group;
• q is an integer from 10 up to 500;
• or in the case where m is greater than 2, is the residue of valency m of a water-soluble polyether polyol having the general formula ##STR9## in which R.sub.3 and m have their previous significance;
• r is zero or an integer from 1 to 500, provided that the total number of ##STR10## units in the molecule is at least 10;
• R.sub.4 is the residue of an organic compound containing in the molecule m hydrogen atoms reactive with an alkylene oxide.