Synthesis And Surface Properties Of A Novel Gemini Zwitterionic Surfactants

Compared with the traditional surfactants, the Gemini surfactants have a highersurface performance, lower c.m.c and Kraft point. As their excellent surfaceproperties, the Gemini surfactants are attracted greatly on colloid and interfacescience areas.A series of Zwitterionic Gemini surfactants were synthesized with polyethyleneglycol, epichlorohydrin, and1,3-Propanesultone through routine organic reactionsuch as etherification, quaternization and sulfonation reaction. With mono-factoranalytical and orthganol methods, some effecting factors such as the reactiontemperature, reaction time, mole ratio of reactants and others were investigated togain the optimum reaction conditions. As results showed that:1) Etherification: themolar ratio of ethylene glycol and epichlorohydrin was1:2.25, and reacted for4h at80℃;2) Quaternization: reacted for16h under refluxing with the molar ratio ofreactants (glycidyl ether/amine) was1:2.2;3) Sulfonation reaction: the reactiontemperature was60℃, reaction time was24hours, the molar ratio of quaternaryammonium salt and1,3-propanesultone was1:3. With the IR, MS and1H-NMR test,indicated that the structures of the products obtained from the synthesis were fullyidentical with the one designed on molecular structure.Further the measurements of the surface property were conducted, it revealedthat all of them were lower c.m.c about10-4~10-5, γc.m.cwere about27~36mN/m. Onthe other hand, we also discussed the effect of concentration, salinity and temperatureon the oil-water interfacial tension.Emulsifying and foaming properties were measured by watershed time method,and the Waring-Blender method respectively. The results showed that both theemulsifying capacity and foam stability were better than the traditional single-chainsurfactants.