glycol polypropylene glycol and polytrimethylene glycol are examples in general alkane diols such as the glycols mention above as well as butane diol pentane diol and hexane diol may be used unchanged or polymerized into polyalkylene glycols generally alkane diols with 2 to 24 carbon atoms may be used unchanged or polymerized into polyalkylene glycols typically the copolymer will have two ester linkages with a polyether chain linking the carbonyl carbons and a polyether chain with one or more ether oxygen atoms extending from the ester oxygens the copolymer may be substituted if desired at any convenient location to add molecular weight or a desired functionality the copolymer may be sulfonated to add surfactant activity the sulfonate groups typically attach at positions alpha to an ester linkage for example at the alpha carbon of the carbonyl oxygen atom the sulfonate groups add anionic charge density to selected locations of the copolymer to provide the linearized charge separation and or dipole moment that gives rise to surfactant activity in aqueous solution the anionic surfactants described above are associated with cations the complex has a structure generally according to the following formula where z represents a cation with a single positive charge examples of which include alkaline metals such as sodium potassium and lithium molecular cations that may be used to maintain solution of the surfactants described above include ammonium trialkylammonium and tris.