羧甲基甘薯淀粉钠的制备及动力学研究

Study on the preparation and dynamic property of sodium carboxymethyl starch

以甘薯淀粉为原料,氯乙酸钠为醚化剂,氢氧化钠为催化剂,乙醇水溶液为溶剂,对羧甲基甘薯淀粉钠的制备及其动力学进行了研究。考察了氢氧化钠用量、氯乙酸钠用量、反应温度和反应时间与羧甲基甘薯淀粉钠取代度的关系。结果表明,制备羧甲基甘薯淀粉钠的较佳工艺条件为:甘薯干淀粉50g,氯乙酸钠15g,氢氧化钠7.8g,反应温度49℃,反应时间2.5h。通过对甘薯淀粉与氯乙酸钠醚化反应的动力学研究表明,甘薯淀粉与氯乙酸钠醚化反应为一级反应。

The preparation and dynamic property of sodium carboxymethyl starch （CMS-Na）were studied by using with sweet potato starch as raw material, sodium chloroacetate as etherization reagent, sodium hydroxide as catalyst and aqueous solutions of ethanol as solvent. The effects of some factors on preparation, such as dosage of sodium hydroxide and sodium chloroacetate, reaction temperature, reaction time on the substitution degree of the sodium carboxymethyl starch were investigated. The results indicated that CMS-Na was preferably prepared as follows： sweet potato starch 50g, sodium chloroacetate 15g and sodium hydroxide 7.8g at 49% for 2.5h. The kinetic study showed that the etherification between sweet potato starch and sodium chloroacetate accorded with the first order reaction kinetic model.