高取代度羧甲基淀粉的合成及性能研究

Synthesis of Carboxymethyl Tapioca Starch with High Degree of Substitution and Properties

以木薯淀粉、氯乙酸为原料,异丙醇为溶剂,多次加碱工艺合成高取代度羧甲基淀粉(CMS)。通过正交实验考察了反应温度、反应时间、反应物料浓度、水的用量对取代度的影响,对影响羧甲基淀粉醚取代度的各因素进行了优化。制备取代度DS>1.3的木薯羧甲基淀粉的原料最佳摩尔比:n[木薯淀粉(以吡喃环单元AGU计)]∶n(氯乙酸)=1∶3,n(氢氧化钠)∶n(氯乙酸)=2.5∶1,醇与水的体积比为19∶1,碱化温度30℃,碱化时间60min,醚化温度50℃,醚化时间120min。

Sodium carboxymethlystarches （CMS） with high degree of substitution （DS） was synthesized from starch and chloroacetic acid in the present of sodium hydroxide. The reaction factors which influenced DS were studied in laboratory experiments on the basis of orthogonality project L16 （4^5）.With the existence of catalyst, the best ratio of the raw materials for preparing CMS with DS〉1.3 was Tapioca starch （AGU） ： epichlorohydrin=1 ： 3; chloroacetic acid ： sodium hydroxide=1 ： 2： 5, the optimum temperature and time are 50 ℃ and 2 h, respectively.