20%茚虫威悬浮剂的热贮物理稳定性预测研究

以20%茚虫威悬浮剂为研究对象,通过研究粒径(D50)、zeta电位及稳定性指数(Turbiscan Stability Index ,TSI)与悬浮剂热贮后物理稳定性之间的相关性,筛选出可快速预测悬浮剂热贮稳定性的评价指标。结果表明:热贮过程中D50、zeta电位绝对值的变化与热贮后的析水率无相关性,与悬浮率的变化存在定性关系,但无定量关系;用稳定性分析仪在54 ℃恒温下短时间扫描的结果显示,TSI能与稳定动力学曲线一起较好地预测悬浮剂热贮前后的外观变化及析水情况,悬浮剂在热贮后发生絮凝与析水之间存在临界Delta BS曲线,TSI(54 ℃,1~5 h)与热贮前后悬浮率的差值呈线性相关。因此,短时间内由D50和zeta电位的变化不能预测悬浮剂的热贮物理稳定性,而利用悬浮剂在54 ℃下短时间内TSI的测试值能快速准确地预测悬浮剂热贮后的物理稳定性。

Research on the prediction of physical stability for indoxacarb 200SC after thermal storage

Indoxacarb 200SC was used to research the correlation of D50,zeta potential and Turbiscan Stability Index(TSI) with the physical stability of suspension concentrate after thermal storage was studied,aiming to screen the evaluation indicators which could predict physical stability of suspension concentrate.The results showed that the changes of D50 and zeta potential during thermal storage had no correlation with water separation rate after thermal storage,and had qualitative relationship but no quantitative correlation with the change of suspension rate before and after thermal storage.However,the scanning results by TurbiscanLabExpert under constant temperature of 54 ℃ for a short time showed that TSI combined with the stability kinetics could predict the change of appearance and water separation rate after thermal storage and there was a critical Delta BS curve which could determine whether flocculation or water separation would occur;And TSI(54 ℃,1- 5 h) had a linear correlation with change of suspension rate before and after thermal storage,especially that TSI(5 h) was the most accurate for predicting the change of suspension rate.All these experiments indicated that the changes of D50 and zeta potential in short time could not predict the physical stability of suspension concentrate after thermal storage,while the TSI(54 ℃)in short time could predict the physical stability of suspension concentrate after thermal storage quickly and accurately.