Synthesis And Application Of Di-diglycerol 2,5-didecylhexanedioate

Gemini surfactant represents a new class of special structure of surfactants, and it is made up of two amphiphilic moieties connected by a spacer group covalently. The separation approach between the Polar head groups within Gemini surfactants is strongly decreased when they aggregate and thus the result is that Gemini surfactant has excellent physical chemistry properties, so it can be widely used in industry. In this thesis, the non-ionic gemini surfactant Di-diglycerol 2,5-didecylhexanedioate was synthesized, and its properties and applications were also studied preliminary.The non-ionic gemini surfactant Di-diglycerol 2,5-didecylhexanedioate was synthesized through esterification, claisen condensation, keto ester alkylation, basic cracking, and transesterification reaction using lauric acid as the initial starting material. On the qualitative and quantitative anaysis of the products of each step, the structure of it was also characterized. Results showed the structure of the final product was proved to be the targeted product originally expected.Surface activity of the gemini surfactant was measured and compared with diglyceryl laurate ester. The result indicated that the surface tension of the gemini surfactant was lower than diglyceryl laurate ester by 12 mN·m-1, cmc and C20 were about an order of magnitude lower;emulsification duration increased by one time;the wetting time and LSDP(%)were 39% and 52% lower respectively. All of these indicated that the gemini surfactant 2,5-didecylhexanedioate has higher surface activity.The antifogging property of 2,5-didecylhexanedioate was tested. Its first drop time and ten drops time were 340s and 90s respectively, both were shorter than diglyceryl laurate ester and the antifogging agent and antifogging film sold in the market. When remixed with other non-ionon surfactact just like T-80, the ratio of T-80 and the gemini was 1:1, the antifogging property is best. Its first drop time and ten drops time were 206s and 53s respectively. At this case the luminousness was 90%, which showed the gemini surfactant to be an excellent anti-fogging agent used in plastic film.