溶剂挥发法制备氟乐灵微胶囊工艺条件

Techniques of Preparing Trifluralin Microcapsules Using Solvent Evaporation Method

为了提高氟乐灵的光稳定性和药效，以聚羟基烷酸酯为壁材，采用溶剂挥发法制备氟乐灵微胶囊，并讨论芯壁比、分散剂质量分数、剪切时间和速度、油水相体积比对氟乐灵微胶囊成囊的影响。结果表明：当芯壁比为1：5，油水相比为20：100～30：90，聚乙烯醇（PVA-1788）的质量分数为1％，剪切时间为3min，剪切速度为8000r／min，所得氟乐灵微胶囊呈球形，平均粒径在6．23～7．57μm，包封率为83．36％，载药量为14．62％。

Microcapsules containing trifluralin were prepared by the solvent evaporation method with poly-β- bydroxybutyrate（PHB） as wall materials in order to enhance its photo-stability and pesticide effect. The encapsulation parameters,including the mass ratio of core materials and wall materials, the concentration of dispersant, shearing time and shearing speed to form an emulsion system, the volume ratio of organic phase and the aqueous phase, were investigated. Optimum parameters to incorporate trifluralin within the PHB microcapsules were showed that mass ratio core materials and wall materials was 1 ： 5, organic phase to aqueous phase ratio ranged from 20 ： 100 to 30： 90, polyvinyl alcohol-1788 （ PVA- 1788） was 1% ,shearing speed was 8000 r/min and lasted 3 min. The obtained microcapsules prepared under the above conditions disperse as individual particles with a spherical shape with the mean particle diameter of 6.23 - 7.57 μm, the loading content and encapsulation efficiency were 14.62% and 83.36%.