Synthesis And Properties Of Trimeric Anionic Surfactant

This dissertation had studied the synthesis, surface chemical properties,effection of NaCl and application properties of a trimeric anionic surfactant:Ⅲ-12S.Ⅲ-12S was firstly prepared by etherealization,ring-opening and sulfation reaction, in which glycerin ,epichlorohydrin , l- dodecanol and chlorosulfuric acid as main materials. The surfactants were characterized by IR, MS and elementary analysis. Through two-phase titrimetric method to determine the active matter content and it was 98.46%.By Du Nouy method, the critical surface tension(γcmc) and critical micelle concentration(cmc) was measured at 30℃,0.2 mol·L-1NaCl , and the result was 28.68mN/m, 4.266×10-5mol/L separately. By calculation, the maximum surface excess concentration (Γmax) and the minimum area per surfactant molecule (Amin) was 2.39μmol/m2, 0.69nm2 separately. It showed perfect surface chemical properties.The micellar properties for the concentration near above the cmc have been characterized by the aggregation number, Nmusing a steady state fluorescence quenching method. The results show that the aggregation number ofⅢ-12S at 30℃is 12 and was stable against temperature.The interactions in the mixed complex with AEO9 have been investigated separately. The cmc value of the mixture was used to computeβm, the interaction parameter in the micelle andβσ, the interaction parameter at the monolayer air–water interface. The value ofβshow there are synergism between complexes.The application properties ofⅢ-12S and the mixed complex with AEO9 were investigated. The results showes that it have a good frothing capacity, solubilizing capacity and high stability in hard water.