毒死蜱的聚脲微胶囊化、表征及毒力评价

Microencapsulation,Characterization and Toxicity Evaluation of Chlorpyrifos

以异佛尔酮二异氰酸酯三聚体和三乙烯四胺为囊壁原料,利用界面聚合法制备了毒死蜱化聚脲微胶囊.通过正交试验研究了微胶囊制备的配方及工艺条件,并用红外和热重对微胶囊的结构及热稳定性进行表征,对微胶囊的缓释性能及对斜纹夜蛾的毒力持效性进行了评价.红外和热重分析结果证实:毒死蜱被成功地微胶囊化,微胶囊结构稳定;正交试验优化条件下的初期包封率超过90%;微胶囊中的毒死蜱在水中30 d释放不超过5%;微胶囊制剂对斜纹夜蛾毒杀的LC50值8 d内从28.32 mg/L变化到31.16 mg/L,表明微胶囊中的毒死蜱持效性良好.

Polyurea microcapsules containning chlorpyrifos were prepared by interfacial polymerization using trimer of isophorone discarnate and triethylenetetramine as membrane materials. Structure and thermal stability of the microcapsule were characterized by FTIR and TGA. The technological conditions were optimized by orthogonal test and the preliminary encapsulation efficiency under the optimized conditions was over 90%. The control-release properties and sustainable toxicity of microcapsules to 3^th-instar larvae of Spodoptera litura were evaluated. The microencapsulated chlorpyrifos release in water during 30 d was no more than 5%. LC50 value for microencapsulated formulation changed only from 28. 32 to 31.16 mg/L within 8 d. It was implied that microencapsulated chlorpyrifos had a sustainable toxicity to S. litura larvae.