Study On The Syntheses And Properties Of Itaconic Acid Ester Sulfonate Gemini Surfactants

In this paper,four novel sulfonate Gemini surfactants?Gemini-12,Gemini-14,Gemini-16 and Gemini-18?were synthesized using itaconic anhydride,sodium bisulfite,long carbon chain fatty alcohols?such as lauryl alcohol,tetradecanol,hexadecanol,and octadecanol?and 1,4-butanediol as raw materials by the monoesterification,sulfonation and diesterification reaction processes.The optimal reaction conditions of the Gemini-12 were obtained via orthogonal experiment.The optimal reaction conditions were obtained via orthogonal experiments.Thus,the first esterificantion reaction was carried out with n?IAn?: n?lauryl alcohol?= 1.05:1.00 at 70 oC for 3.0 h.The sulfonation reaction was carried out with n?monolauryl itaconate?: n?sodium bisulfite?= 1.00:1.25 and 40 % solid content at 90 oC for 4.0 h.The diesterification reaction was carried out with n?sodium lauryl sulfoitaconic monoester?: n?1,4-butanediol?= 2.30:1.00 and 1.0 % p-methyl benzenesulfonic acid at 150 °C for 6.0 h.Then Gemini-14,Gemini-16 and Gemini-18 were synthesized on the basis of the optimum process conditions.The structures of intermediates and and target products were characterized by FT-IR and 1H NMR.The final products were confirmed as the target products through the spectrum analysis.On the basis of structural confirmation,the physico-chemical properties of the itaconic acid ester sulfonate Gemini surfactants were systematically studied.The results showed that,compared with the traditional sulfonate surfactants,the four Gemini surfactants have lower surface tension and the critical micelle concentration?CMC?,lower Krafft point,greater maximum surface excess??CMC?,smaller minimum area per molecule?ACMC?,excellent wetting properties,good foam properties,lime soap dispersing power,and emulsifying properties.The minimum surface tension of the Gemini-12 is 28.615 mN/m,and the CMC value of Gemini-18 is 3.311×10^-4 mol/L.The critical micelle concentration of the itaconic acid ester sulfonate Gemini surfactants affected by several kinds of inorganic salt additives was systematically studied by changing the concentration of the cation,the valence of the cation,as well as the species of anions in inorganic salt and other parameters.The results showed that with the increase of the concentration of the NaCl,the CMC value of Gemini-12 decreased.When the same concentration of Na Cl,ZnCl₂ and AlCl₃ were added,the CMC values were lower than that without adding inorganic salt,and the order of decreasing CMC value was Zn²⁺>Al³⁺>Na⁺.When adding the same concentration of NaF,NaCl,Na Br inorganic salt additives,the critical micelle concentration of Geminin decreased,but the effect was not very obvious.In order to further improve the performance of Gemini surfactants,the critical micelle concentration of mixed system blended the itaconic acid ester sulfonate Gemini-n series surfactants with traditional nonionic surfactant NP-10 was studied,and the results showed that Gemini-n and NP-10 mixed system have higher surface activity,especially the CMC value of Gemini-18 complex system is significantly reduced,reaching to 1.95×10-5 mol/L.That is to say the synergetic efficiency of the Gemini-n and NP-10 mixed system was obvious.