苄基淀粉醚与烷基多糖苷复配制备氰氟草酯水乳剂

摘要

以苄基淀粉醚与烷基多糖苷复配为乳化剂,油酸甲酯为溶剂,采用浓缩乳化法制备了高度稳定的10％氰氟草酯水乳剂.分析了苄基淀粉醚的红外和紫外特征图谱.采用正交试验设计,通过测定乳滴粒径分布,结合乳液外观,研究了乳化方法、预处理液中苄基淀粉醚与烷基多糖苷质量分数、转速和剪切时间等工艺条件对乳液稳定性的影响.结果表明,苄基淀粉醚与原淀粉相比,在红外、紫外光照射下出现了苯甲基的特征吸收峰.以苄基淀粉醚与烷基多糖苷质量比3∶2复配为乳化剂、质量分数9％油酸甲酯为溶剂制备的10％氰氟草酯水乳剂,乳滴平均粒径在1.02 μm左右,且经(54±2)℃密封14 d加速试验和常温储存6个月后,平均粒径仅增长0.1 ～0.6 μm,析水率为2.7％,均优于用常规乳化剂和溶剂制备的10％氰氟草酯水乳剂.因此,苄基淀粉醚与烷基多糖苷以及油酸甲酯可作为备选乳化剂和溶剂,用于环境相容性好的农药剂型加工.%To replace the common emulsifiers and solvents,the mix-emulsifier of benzyl starch ether in combination with alkyl polyglycoside and solvent of methyl oleate were used in preparation of 10％ cyhalofopbutyl aqueous emulsions.The structure of benzyl starch ether was characterized by FTIR and UV spectroscopies in case of benzyl carboxymethy.The effects of different processing parameters,including the concentration of benzyl starch ether and alkyl polyglycoside in pretreatment fluid,rotation speed and shearing time on the stability of emulsion were studied by measuring oil droplet diameter distribution and using the orthogonal experimental design.The results demonstrate that benzyl starch ether compared with pristine starch has absorption peak of benzyl carboxymethyl.High stable emulsions can be prepared with benzyl starch ether and alkyl polyglycoside complex in 3∶2 molar ratio as emulsifier and 9％ methyl oleate as solvent.The mean droplet diameter of emulsions is about 1.02 μm and is increased by only 0.1 ～ 0.6 μm after storing at 25 ℃ for 6 months or at (54 ±2) ℃ for 14 days and the water separating proportion is only 2.7％.Cyhalofop-butyl oil-in-water emulsion prepared with benzyl starch ether,alkyl polyglycoside and methyl oleate has a better stability than the conventional emulsions.The results of this study show that benzyl starch compounding with alkyl polyglycosid and methyl oleate can be used as an alternative emulsifier and solvent for the environmentally friendly oil-in-water emulsion formulations.