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

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• 作者：Zhiyi XIE ; Nengchang CHEN ; Chengshuai LIU ; Jianmin ZHOU ; Shengguang XU ; Yuji ZHENG ; Fangbai LI ; Yanling XU
• 关键词：Na₄-EDTA microcapsules ; interfacial polymerization ; controlled release
• 刊名：Chinese Journal of Chemical Engineering
• 出版年：2010
• 出版时间：February 2010
• 年：2010
• 卷：18
• 期：1
• 页码：149-155
• 全文大小：521 K

文摘

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 6 μm, 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·min⁻¹, stirring time 30 min, and the ratio of the wall materials to core materials 0.15.