【摘要】 羧甲基淀粉和羟乙基淀粉作为两种重要的变性淀粉,由于其合成条件苛刻和稳定性差等缺点限制了其应用。以甲醇为溶剂,筛选出四正丁基溴化铵(TBAB)作为相转移催化剂(PTC)对淀粉进行羟乙基化,合成了高取代度的羟乙基淀粉,并采用氯乙酸对其进行醚化,合成了羧甲基-羟乙基淀粉,既降低了传统合成方法的危险性,又克服了羧甲基淀粉的不稳定性。通过单因素分析对合成工艺进行了优化,优化条件为:淀粉25 g,催化剂0.75 g2,-氯乙醇10.0 g,NaOH 8.0 g,氯乙酸10.5 g,溶剂含水量为9 mL,羟乙基化反应时间为6 h。试验证明,相转移催化法制得的产品取代度高,稳定性好。更多还原

【Abstract】 As two important kinds of modified starch,carboxymethyl starch and hydroxyethyl starch are limited in their application because of their rigorous preparation process and unstability.In this paper,the hydroxyethyl starch was produced by a methanol solvent method.We selected tetrabutyl ammonium bromide(TBAB)as the phase transfer catalyzer(PTC)to synthesize hydroxyethyl starch with higher degree of substitution.Then,with chloroacetic acid as etherifying agent,we synthesized carboxymethyl-hydroxyethyl starch with good stability in a safe method.The single factor analysis was established to conduct process optimization.The optimization was as follow:starch:25 g,catalyst:0.75 g,2-chlorine ethanol:10.0 g,NaOH:8.0 g,chloroacetic acid:10.5 g,water content of solvent:9 mL,and hydroxyethylation reaction time:6 h.It was proved that the product prepared by this method had high degree of substitution and good stability.更多还原