Synthesis And Application Of Novel Nonionic Gemini Polyglycerol Esters Surfactants

Two kind of intermediates are synthesized through Claisen condensation, and substitution using ethyl caprylate, ethyl formate, metallic sodium, 1,2-dibromoehane, 1,6-dibromohexane, and absolute alcohol as materials. After the intermediates are separated and purified, they are analyzed by the following examining methods: IR and 1H NMR and proved to be the intermediates as originally expected. The final products (G121, G222 and G323) of nonionic Gemini surfactant can be synthesized by transesterification the intermediates with the glycerol or polyglycerol.The non-ionic Gemini surfactants G121, G222 and G323 have more excellent properties compared with conventional single-chain surfactant glycerol caprylate, the surface tension of theirs are 28.8, 30.0 and 31.5mN m^-1, respectively, the CMC values of theirs were 0.0045, 0.0040 and 0.0038mmol L^-1, respectively, the properties of theirs, including wetting ability (are 36, 33 and 28s, respectively), soap dispersancy(are 20%, 18%, 15%, respectively), emulsifying capability (are 7.11, 5.69 and 5.66min, respectively) and anti-drop property are better.