造纸助剂二乙烯三胺五乙酸的合成研究

Synthesis of Diethylenetriaminepentaacetic Acid as Papermaking Additive

采用氯乙酸法合成二乙烯三胺五乙酸(DTPA)。考察了反应终点pH值、反应温度、反应时间等因素对产率的影响,确定合成DTPA的优化条件为:反应温度65℃、反应时间5 h,采用浓硫酸酸化,调节反应终点pH值为2.5,酸化温度低于40℃。在优化条件下,DTPA的产率达到73%以上。对结晶母液进行处理,DTPA的回收率约为8%。测定了产物的螯合值,并对产物进行红外光谱表征。

Diethylenetriaminepentaacetic acid （DTPA） was synthesized by chloroethanoic aeid method. The influences of pH value in the end of reaction, reaction temperature, and reaction time on the yield of the product were investigated. The optimum conditions were obtained as follows： the reaction temperature was 65 ℃, the reaction time was 5 hours, the pH value in the end of reaction adjusted with sulfuric acid was 2.5, the acidification temperature was less than 40 ℃. Under the optimum conditions, the yield of the product reached 73%. The recovery rate of the product from crystal mother liquor was about 8%. The chelating value of the product was measured. The product was characterized by IR.