天冬氨酸-柠檬酸共聚物对碳酸钙的抑制性能

Inhibition of Copoly(Aspartic acid-Citric acid) to Calcium Carbonate Scaling

摘要:

以天冬氨酸和柠檬酸为原料，采用微波加热共聚合成法对天冬氨酸进行聚合改性制备了天冬氨酸-柠檬酸共聚物（PAC），参照静态阻垢法，以碳酸钙为目标垢型，考察了PAC对碳酸钙的抑制性能、与阻垢剂（HEDP）的配伍性能以及阻垢性能对比，采用FTIR、NMR、AFM和XRD对PAC和碳酸钙晶体的形态、结构进行了表征。结果表明：天冬氨酸和柠檬酸通过酰胺化、水解聚合反应合成了PAC。PAC对碳酸钙垢具有极好的抑制作用，其抑制作用强于HEDP。当PAC投加量为6.4mg/L时，PAC对碳酸钙的抑制率达95.04%；PAC与HEDP配伍性较好，PAC/HEDP的阻垢、缓蚀效果均优于PAC。AFM和XRD分析结果表明：PAC改变了碳酸钙晶体的形态和结构，由热力学最稳定的方解石转变为最不稳定的球霰石。

Abstract:

Copoly(Aspartic acid-Citric acid)(PAC) was prepared by copolymerizing aspartic acid and citric acid under microwave heating. Referring to the static scale inhibition method, the inhibition performance of PAC as CaCO3 scale inhibitor and the inhibition contrast and compatibility performance of PAC with HEDP were investigated. The morphology and structure of CaCO3 crystals and PAC were characterized by FTIR, NMR, AFM and XRD. The results showed that the synthesis of PAC was from aspartic acid and citric acid by the polymerization reaction of amidation and hydrolysis. PAC had excellent inhibition on CaCO3 scale, and its inhibition effects were superior to HEDP. The inhibition efficiency of PAC on CaCO3 reached 95.04% when the dose was 6.4 mg/L. PAC had better compatibility performance with HEDP, the inhibition effects of PAC/HEDP were superior to PAC. The analysis results of AFM and XRD showed that the morphology and structure of CaCO3 crystals were changed by PAC, transforming the most stable’s calcite into the most unstable’s vaterite.