淀粉与2-氯乙醇醚化反应的研究(英文)

A Study on Starch Etherification with 2-Chloroethanol

对在水溶液中不同反应条件下淀粉与2-氯乙醇醚化的反应进行了研究。考察的因素包括碱处理时间与温度、氢氯化钠及2-氯乙醇的用量以及醚化时间与温度。结果表明,碱处理时间超过40min,摩尔取代度没有明显的变化。摩尔取代度随氢氧化钠用量的增加而提高,但达到最大值后则会降低。随醚化时间的延长,摩尔取代度增大,但10h以后则变化不大。醚化温度在53℃时可以得到较高的摩尔取代度。

In water solution, etherification of starch with 2-chloroehanol is investigated under different conditions. Factors studied include alkali treatment time and temperature, amount of sodium hydroxide and 2-chloroehanol as well as etherification time and temperature. Results obtained indicate that the degree of molar substitution（MS） has no apparent changes for longer than 40min alkali treatment, MS increases as the amount of sodium hydroxide increases. It attains a maximum and then decreases, prolonging the reaction time up to 10h is accompanied by enhancement in the extent of etherification. Longer reaction time has no effect on MS. The etherification temperature being higher or lower than 50℃causes a decrease in MS.