sorbitan monolaurate(Span 20)is a famous nonionic surfactant which possesses many excellent properties such as emulsifying,dispersing,nontoxic,nonirritant and lowvolatilization.Span 20 was synthesized from sorbitol and laurate by onestep method which made the etherification and esterification work simultaneously.The synthesis method was compared and the main influencing factors on the products color and three targets(acid number,hydroxide value and saponification value)such as reacting temperature and time were also studied.Finally,the suitable conditions for the synthesis of Span 20 products were obtained,i.e.,reaction temperature 215°C,reaction time 240 min and w(phosphoric acid)=043%.The analysis results showed that the experimenting samples’three targets were eligible,the color was ivory,and it’s monoester massfractions was higher than 90%.
