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 sorbito...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%.展开更多
研究了微波-表面活性剂协同提取法(MAME)提取山竹外衣色素的工艺条件与过程。考察了提取剂中表面活性剂类型和含量、提取液pH、微波提取功率、时间、浸泡固液质量比和时间对色素提取率的影响,实验结果表明:pH=1时,以w(聚氧乙烯十二酸失...研究了微波-表面活性剂协同提取法(MAME)提取山竹外衣色素的工艺条件与过程。考察了提取剂中表面活性剂类型和含量、提取液pH、微波提取功率、时间、浸泡固液质量比和时间对色素提取率的影响,实验结果表明:pH=1时,以w(聚氧乙烯十二酸失水山梨醇单酯)=0.08%的乙醇溶液〔φ(CH3CH2OH)=70%〕为提取剂,山竹外衣按m(山竹外衣)∶m(提取剂)=1∶263浸泡于提取剂中5 m in、微波功率800 W下提取25 s,色素提取率为96.26%。该法一次提取率是传统溶剂法的1.78倍,提取时间是溶剂法的1/240,聚氧乙烯十二酸失水山梨醇单酯对色素提取有增溶作用。展开更多
文摘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%.
文摘研究了微波-表面活性剂协同提取法(MAME)提取山竹外衣色素的工艺条件与过程。考察了提取剂中表面活性剂类型和含量、提取液pH、微波提取功率、时间、浸泡固液质量比和时间对色素提取率的影响,实验结果表明:pH=1时,以w(聚氧乙烯十二酸失水山梨醇单酯)=0.08%的乙醇溶液〔φ(CH3CH2OH)=70%〕为提取剂,山竹外衣按m(山竹外衣)∶m(提取剂)=1∶263浸泡于提取剂中5 m in、微波功率800 W下提取25 s,色素提取率为96.26%。该法一次提取率是传统溶剂法的1.78倍,提取时间是溶剂法的1/240,聚氧乙烯十二酸失水山梨醇单酯对色素提取有增溶作用。
