绿色螯合剂亚氨基二琥珀酸的合成及螯合性能

亚氨基二琥珀酸是一种新型的氨基多羧酸螯合剂,有着很强的螯合过渡金属离子的能力,并具有良好的降解性,被称为绿色化学品。本文研究了用顺丁烯二酸酐(MA)、氢氧化钠、氨在水溶液中合成亚氨基二琥珀酸的工艺和反应机理,考虑了温度、原料配比和反应时间等对产品收率的影响,研究了亚氨基二琥珀酸的螯合性能,并与经典的螯合剂EDTA做了比较。结果表明,合成反应较合适的原料摩尔比n(MA)∶n(NaOH)∶n(NH3)∶n(H2O)=2∶3∶2∶16,较好反应温度160℃,反应时间10.0 h。在该反应条件下,亚氨基二琥珀酸的收率大于80.0%;反应很可能是顺丁烯二酸与氨生成天门冬氨酸,天门冬氨酸再与顺丁烯二酸反应生成亚氨基二琥珀酸;亚氨基二琥珀酸对大多数金属的螯合能力接近EDTA的水平,有些甚至超过EDTA。

Synthesis of Iminodisuccinic Acid and Its Chelating Ability

Iminodisuccinic acid(NH(COOHCHCH_2COOH)_2,IDS) is a green chelating agent with amino and polycarboxylic groups,which forms strong water-soluble complexes with various metal cations and is readily biodegradable.IDS was synthesized with maleic anhydride(MA),ammonia(NH_3)and NaOH in an aqueous medium.The process and principle of the synthesis were discussed.The effects of temperature,raw material ratio,reaction time on the yield product were analyzed.The better conditions were found as follows: MA∶NaOH∶NH_3∶H_2O(mol ratio)=2∶3∶2∶16,160 ℃,10.0 h.Under these conditions,up to 80.0% yield of iminodisuccinic acid was obtained.The results indicated that iminodisuccinic acid might be formed through the formation of aspartic acid as the intermediate.The chelating ability of IDS was studied and was compared with EDTA and the results showed that the chelating ability of IDS for many metals was similar to that of EDTA.