柠檬酸氢钙水合物的制备与表征

摘要

针对柠檬酸与碳酸钙反应制备柠檬酸氢钙的过程，采用FTIR、EA、TGA和PXRD等表征方法，研究了不同温度下的反应结晶机理、结晶产品及其结晶水含量。实验发现，在柠檬酸与碳酸钙的反应过程中，首先生成柠檬酸钙，当起始柠檬酸与碳酸钙摩尔比≥2：3时，柠檬酸钙可与剩余的柠檬酸继续反应生成柠檬酸氢钙。其中，当反应温度20℃以下，最终结晶产品为柠檬酸氢钙三水合物；当反应温度40℃以上，最终结晶产品为柠檬酸氢钙一水合物；当反应温度20~40℃，最终结晶产品则为柠檬酸钙四水合物。%The monohydrate and trihydrate of calcium hydrogen citrate were firstly prepared and character-ized by use of FTIR,EA,TGA and PXRD. Meanwhile,the reaction progress of citric acid and calcium car-bonate was investigated as well. In general,calcium citrate is firstly obtained after the reaction of citric acid and calcium carbonate,and then transforms respectively into monohydrate or trihydrate of calcium hy-drogen citrate at different temperatures when the initial reactant molar ratio of citric acid and calcium car-bonate is larger than 2:3. The final crystallization products will be calcium hydrogen citrate monohydrate, calcium hydrogen citrate trihydrate and calcium citrate tetrahydrate respectively when the reaction temper-ature is 20~40 ℃.