Synthesis And Properties Of Itaconic Acid-based Asymmetric Diester Sodium Sulfonate Surfactant

In this paper,itaconic anhydride,lauryl alcohol polyoxyethylene ether,lauryl acid monoethanolamide were used as the main raw materials,and sodium hydrosulfite was used as the sulfonation agent.A series of itaconi c acid-based asymmetric diester sulfonate surfactant(gemini-n(n=3,5,7,9))were synthesized by single esterification reaction,double esterific ation reaction and sulfonation reaction,which were not reported in the lit erature.The preparation and properties of the series of surfactants were st udied in order to obtain a class of environmentally friendly new itaconic acid-based anionic gemini surfactants.In the first part,gemini-n surfactants were prepared and characterized.Taking the synthesis of gemini-9 as an example,the optimum process co nditions for its monoesterification,diesterification and sulfonation were de termined by orthogonal experiment.Thus,the monoesterification reaction was carried out with n(IAn):n(AEO-9)=1:1 at 110?for 3.0 h.The biest erification reaction was carried out with n(Lauryl alcohol polyoxyethylene ether itaconate acid monoester):n(LMEA)=1:1.5 at 140?for 5.0 h.The sulfonation reaction was carried out with n(IAn):n(Na HSO₃)=1:1.1 and1%catalyst in total system at 90?for 3.5 h.On the basis of these opt imal process conditions,the target products gemini-3,gemini-5,gemini-7were synthesized.A series of gemini-n intermediates and target products were characterized by FT-IR and ¹H NMR.The successful synthesis of ge mini-n surfactant was confirmed.In the second part,based on the structural confirmation,the physicoc hemical properties of gemini-n were systematically studied.The surface te nsion,critical micelle concentration,emulsifying properties,foam propertie s,calcium soap dispersion,wettability and salt resistance of gemini-n wer e studied.At the same time,the effect of the number of EO groups on t he physicochemical properties of gemini-n was discussed.The results sho w that gemini-n has good foam properties,emulsifying properties and exc ellent calcium soap dispersion,wettability and salt resistance.Among the m,the minimum surface tension of the gemini-5 was 32.35 m N/m,and the cmc value of gemini-9 was 2.11×10^-5mol/L.The third part studies the compound performance of gemini-9 surfacta nt.The surface activities and application properties of gemini-9/CTAB(hexadecyl trimethyl ammonium bromide)and gemini-9/CAB(coconut oil amide propyl betaine)with different ratios were investigated,and th e synergistic effect of the two complex systems was verified by the norm al solution theory.The effects of various alcohols and salts on the surfac e properties of gemini-9/CTAB composite system were mainly explored.The results showed that the two composite systems showed good synergist ic effects in surface activity and emulsifying properties.When the Na Cl c oncentration was 0.1 mol/L,the surface performance of the composite s ystem was excellent;The ability of different salts to improve the surface activity of compound system was:MgCl₂>KCl>NaCl.When?(N-b utanol)=10g/L,the surface activity of the compound system was the best.The ability of different alcohols to improve the surface activity of t he compound system is:N-butanol>1,3-butanediol>1,2,4-butanetriol.