Surfactants from glucamines and ω-epoxy fatty acid esters

The ring-opening reaction of ω-epoxy fatty acid methyl esters (9,10-epoxy decanoic acid methyl ester, 10,11-epoxy undecanoic acid methyl ester and 13,14-epoxy tetradecanoic acid methyl ester) with N-methyl glucamine or glucamine was studied. A new method (in methanol under reflux) leads to products, which are surfactants of linear-or Y-type-structure, in fair yields and purities. In a following step the ring-opening products were saponificated by enzymatic catalysis or by conversion with sodium hydroxide leading to amphoteric surfactants. The surface-active properties of the methyl esters and their corresponding acids or salts were studied at various pH-values by measurement of surface tension of aqueous solutions and by examination of foaming properties. Depending on the chain length of the used epoxides, the structure of the obtained sugar-based surfactant and the pH-values, different surface-active properties were observed. Several of the achieved products reduce the surface tension of aqueous solution down to 26-40 mN/m. Examination of foaming properties of the latter show rather poor or good foamers, depending on the surfactant used or the pH-value of the solution. La reaction d'ouverture de cycle des esters methyliques ω-epoxy d'acides gras avec la N-methyl glucamine ou la glucamine est etudiee. Un nouveau procede (dans le methanol sous reflux) conduit a des tensioactifs de structure lineaire ou de type Y avec des puretes et rendements satisfaisants. Lors d'une etape ulterieure, les produits sont saponifies par catalyse enzymatique ou par conversion avec NaOH pour donner des tensioactifs amphoteres. Les proprietes tensioactives des esters methyliques et des acides ou sels correspondants sont etudiees a differents pH en mesurant la tension superficielle des solutions aqueuses et en examinant le pouvoir moussant.