界面聚合法制备新型防蚊微胶囊

New-type Anti-mosquito Microcapsules Prepared by Interfacial Polymerization

采用界面聚合法,研究了以聚脲为壁材、含残杀威防蚊微胶囊的制备工艺。探讨了复合乳化剂、芯壁比、反应时间、反应温度和搅拌速率对微胶囊粒径及其分布、包埋率、水解率和结构的影响。研究结果表明,影响微胶囊制备主要因素是芯壁比和反应时间,次要因素是反应温度和搅拌速率。最佳制备工艺:吐温80和司班80以1∶1的复配比作为乳化剂,芯壁比1∶2.5、反应时间3.5 h、反应温度60℃、搅拌速率550 r/min时,制得微胶囊包埋率为75.8%,水解率为20.7%,平均粒径为2.341μm,粒径分布均匀。经红外光谱分析和扫描电镜观察得出已成功制备球形微胶囊。生物测试结果表明其具有长效防蚊效果。

By adopting the interfacial polymerization method, anti-mosquito microcapsules using polyurea as wall material and containing Propoxur were prepared. This paper discusses the influence of composite emulsifier, core-wall ratio, reaction time, reaction temperature and stirring speed on the particle size and distribution of microcapsule, encapsulation efficiency, hydrolysis rate and structure. Results show that main factors that infuence microcapsule preparation are core-wall ratio and reaction time, and the secondary factors are reaction temperature and stirring speed. The optimized condition of the microcapsules preparation is as follows： preparing the emulsifer by using Tween80 and Span80 at 1∶1 ratio, the core-wall ratio is 1∶2.5, reaction time is 3.5 hours, reaction temperature is 60 ℃ and stirring speed is 550 r/min. The microcapsules prepared under this condition have 75.8% of encapsulation efciency, 20.7% of hydrolysis rate, and 2.341 μm of average particle size with a uniform distribution. FTIR analysis and SEM observation verify that spherical microcapsules have been successfully prepared. And the biological test proves that this kind of microcapsule has long-lasting anti-mosquito property.