Synthesis and Quantitative Determination of Gemini Surfactants

摘要

The intermediate 1-bromo-2-(2-bromoethoxy)ethane was synthesized from diglycol and phosphorus tribromide. Cationic Geminisurfactants, diethyl ether-bis-(dimethyl alkylammonium bromide) were synthesized from the intermediate and tertiary amines with differentalkyl chains by using isopropanol as solvent. The reactants were recystallized in the ethyl acetate-ethanol solvent mixture (volume ratiois 2:1), the yields were all up to 70 %. The Gemini surfactants were characterized by infrared and ~1H NMR analysis and were alsoquantitatively determined by the two phase chemical titration using bromophenol blue as the indicator and chloroform as the phasedispersing agent. The results showed that the purity of the six Gemini surfactants synthesized are greater than 96 % in weight.