Synthesis and Characterization of Ethylenediamine Tetraacetic Acid Tetrasodium Salt Loaded in Microcapsules with Slow Release Properties

• Published in: Chinese journal of chemical engineering Vol. 18; no. 1; pp. 149 - 155
• Main Author: 谢志章 陈能场 刘承帅 周建民 徐胜光 郑煜基 李芳柏 徐燕玲
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2010
• Subjects: controlled release; EDTA; Emulsifiers; Ethylenediamine; interfacial polymerization; Monomers; Morphology; Na 4-EDTA microcapsules; Optimization; Stirring; Synthesis; Walls; 乙二胺四乙酸; 墙体材料; 微胶囊; 性能表征; 扫描电子显微镜; 最佳合成条件; Na 4-EDTA microcapsules; controlled release; interfacial polymerization
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/S1004-9541(08)60336-5

The microcapsules with cores of ethylenediamine tetraacetic acid tetrasodium salt（Na4-EDTA）and walls of polyurea were synthesized via an interfacial polycondensation reaction with 2,4-tolylene diisocyanate as an oil-soluble monomer and diethyl triamine as a water-soluble monomer.Various manufacturing parameters,including the amount of emulsifier,agitation speed,stirring time and ratios of the wall materials to core materials,were altered to optimize process variables during the synthesis of microcapsules,and the effects of these parameters on the characteristics of the microcapsules were examined.The structure,morphology,mean particle size and size distribution were characterized by optical microscope and scanning electron microscopy（SEM）,showing that the mean diameter of optimal microspheres was approximately 6μm,and microcapsules were spherical.In vitro release of Na4-EDTA from these microcapsules was performed in distilled water.Under the optimal preparation conditions, the Na4-EDTA release profiles were biphasic with a burst release followed by a gradual release phase.After an initial burst,a continuous Na4-EDTA release was up to 5-7 days.The optimal synthesis conditions for the microcapsules with stable,good morphology and good controlled-release properties were as follows：emulsifier Span-80 10% （by mass）,agitation speed 900 r·min1,stirring time 30 min,and the ratio of the wall materials to core materials 0.15.