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采用界面聚合法,以薄荷素油为芯材,以异佛尔酮二异氰酸酯为壁材单体,在催化剂四甲基乙二胺作用下和水反应形成聚脲外壳,制备出了薄荷素油微胶囊.通过扫描电镜、激光粒度分析仪、傅里叶红外光谱仪及热重分析仪分别对香精微胶囊的表面形貌、粒径分布、单体反应情况和热稳定性进行了分析表征.通过紫外可见分光光度计对香精微胶囊包覆率进行了测定.并分析了均质化速率和微胶囊平均粒径的关系以及不同乳化剂种类和芯壁比条件下微胶囊的形貌特征.结果表明,微胶囊平均粒径随均质化速率的增大而减小,下降到1μm左右时趋于平稳,当乳化剂采用聚乙烯醇且芯壁比为4∶1时,微胶囊形貌最佳,为规整球形.最终测得微胶囊芯材包覆率为84.09 wt%,粉末状微胶囊样品含油率为72.64 wt%,并且微胶囊芯材具有良好的热稳定性.
Adopting the interfacial polymerization method, using menthol oil as the core material and isophorone diisocyanate as the wall material monomer, reacting with water under the catalyst of tetramethylethylenediamine to form a polyurea shell, a microcapsule microcapsule was prepared The surface morphology, particle size distribution, monomer reaction and thermal stability of the fragrance microcapsules were characterized by scanning electron microscopy, laser particle size analyzer, Fourier transform infrared spectrometer and thermogravimetric analyzer, respectively. The coverage of the microcapsules was determined by spectrophotometer.The relationship between the homogenization rate and the average diameter of the microcapsules and the morphologies of the microcapsules under different emulsifier types and core-wall ratios were analyzed.The results showed that, The average diameter of the microcapsules decreased with the increase of the homogenization rate. When the average diameter of the microcapsules decreased to about 1μm, the microcapsule morphology was the best when the emulsifier was polyvinyl alcohol and the ratio of core to wall was 4:1. The results showed that the encapsulation rate of the microcapsule core was 84.09 wt%, the oil content of the powdery microcapsule was 72.64 wt%, and the microcapsule core had good thermal stability.