New oligomeric surfactants with multiple-ring spacers: Synthesis and tensioactive properties

Abstract

New anionic oligomeric (tetrameric) surfactants with different spacing architecture based on dioxane rings were synthesized, and their surface-active properties were studied. The synthesis of these compounds involves a three-step procedure comprising tetraglycidyl ethers as key intermediates for connecting four amphiphilic moieties. Critical aggregation concentration (CAC), surface tension at the CAC (γ CAC), ability of these compounds to lower surface tension by 0.02 N/m ( C 20 and p C 20), estimated values of the surface area occupied by the surfactant headgroups ( a), and packing parameter ( P) values are reported at 20 and 40 °C. The molecular architecture of these compounds influences strongly the values of these physicochemical parameters. It was found that the ability of these compounds to lower surface tension is good, but the high relative propensity to form aggregates is their distinctive feature. This ability of aggregation is favored as the number of dioxane rings in the spacer group increases and the spacer group is less flexible.