Study Of Gemini Phosphate Salt

Gemini phosphate surfactants were reputed as a new generation of surfactants. As a special structure with two hydrophilic head groups and two hydrophobic groups, they have some especial physical and chemical characteristics such as low cmc and high surface activities. In this paper, two novel gemini phosphate surfactants were synthesized, their structures were determined and the properties were studied.The gemini phosphate surfactant was synthesized with phosphatizing agent P₂O₅ by three steps:The first step, a decyl glycide ether was prepared by reaction of intiator long-chain alkyl alcohol with epichlorohydrin in the presence of phase transfer catalyst. Purification of reaction mixture was performed by reduced pressure and the productivity was 79.9%.By analying the IR and epoxy value of aim product, the structure was confirmed.The second step, the decyl digomeric glycol-intermediate product of gemini phosphate surfactant was prepared by opening ring reaction of decyl glycide ether in the presence of potassium as catalyst. Purification of reaction mixture was performed by reduced pressure and the productivity was 65.4%.The structure was determined by ¹H-NMR and IR.The third step, the gemini phosphate surfactant was synthesized the decyl digomeric glycol and phosphatizing agent P₂O₅ by phosphatation. The reaction mixture was separated by the chromatography, the structure determined by ¹H-NMR and IR.The gemini phosphate surfactant was synthesized with phosphatizing agent POCl₃ by two steps:The first step, the compound of which the spacer group is polymethelene was prepared by POCl₃ and ethylene glycol, and the productivity was 95.6%.The second step, the gemini phosphate surfactant was synthesized with a-decyl alcohol and phosphatizing agent POCl₃ by phosphatation. Purification of reaction mixture was performed by reduced pressure and the productivity was 90.6%.The structure was determined by ¹H-NMR and IR. It was found that two steps in phosphating the gemini phosphate were better than three steps in phosphating the gemini phosphate, and the productivity of the first method was 90.6%.In addition, some properties of two gemini phosphates were tested and the connection between structure and properties were discussed. The experiments results indicated that the gemini phosphate surfactant have lower cmc, better wettability , better emulsifier. They also had better antistatic property and property of friction.