植物油电化学法合成环氧化合物

Synthesis of vegetable oil epoxides with electrochemical method

采用电化学合成法对植物油进行环氧化合物的合成。通过L_(18)(3~7)正交试验讨论了蓖麻油电化学环氧化的制备工艺条件。采用红外光谱(FT-IR)和热重分析(TG)对植物油及相应环氧化合物的结构进行了表征。实验所得优化工艺条件为:反应时间为4 h,p H=6.5,反应温度为30℃,通氧速率为3 cm^3/s,电流密度为0.3 A/cm^2,蓖麻油双键与HCOOH的摩尔比为8,催化剂(0.1 mol/L盐酸)用量为0.3 m L(相对于40 g蓖麻油),在此条件下所得环氧化蓖麻油相对环氧产率达53.7%。FT-IR分析表明,电化学反应后植物油中-C=C-消失,出现了含有-C-O-C-的新物质;TG分析表明,在一定条件下,-C-O-C-的热稳定性较-C=C-强。这表明植物油电化学法合成环氧化合物是可行的。此外,对大豆油、玉米油和花生油这3种植物油做了同样的验证。

Vegetable oil epoxides were synthesized with electrochemical method. The optimum conditions forcastor oil epoxidation technology were determinated by L18 （37 ） orthogonal test. The starting material castor oilas well as its epoxidized derivatives was characterized and compared by F-I＂ - IR and TG analysis. Experimentalresults showed that the optimum conditions are：reaction time,4 h;pH value ,6.5 ;reaction temperature ,30 ℃ ;oxygen flow rate,3 cm3/s ; current density ,0.3 A/cm2 ; molar ratio of castor oil double bonds to HCOOH, 8 ;and catalyst （0. 1 mol/L hydrochloric acid） dosage, 0. 3 mL. Under such conditions, the relative yield ofepoxidized castor oil achieves 53.7%. The FT - IR spectra indicated that new material containing - C - O - C -group was produced accompanying with the disappearance of - C = C - group ; and TG analysis indicated thatthe thermal stability of - C - O - C - groups is stronger than that of - C = C - groups under certainconditions. Such results suggested that synthesis of vegetable oil epoxides with electrochemical method isfeasible. In addition, similar tests for using of soybean oil, corn oil and peanut oil were also done.