影响农药水乳剂稳定性因素与控制(下)

Factors Influencing the Stability of Pesticides EW Formulations and Controlling Measures(2)

目前国内研发并投放市场的水乳剂产品与国外产品相比有较大差距,主要表现在国内产品在常温贮存过程中,易产生分层、沉降和析出晶体的情况,从而药效降低。论述有关影响水乳剂稳定性因素(包括分层或沉降、絮凝、聚结或破乳、奥氏熟化和转相)。详细讨论了从乳化剂的选用、乳化剂的用量、液滴大小及分布、温度和黏度来控制水乳剂稳定性。指出水乳剂一般在热贮和冷贮与常温长期贮放条件下其稳定性间并无内在联系。水乳剂的经时稳定性是二年货架寿命重要保证。粒度分布仪和全能稳定性分析仪可用来预测水乳剂稳定性。

At present marketed EW products in domestic have big disparity compared with foreign products which are mainly easy to have these changes of stratification,sedimentation and crystallization while stored in room temperature.This article described related factors influencing EW stability（including stratification or sedimentation,flocculation,coalescence or deemulsification breaking, ostwald ripening and phase transition ）.Such factors as emulsifier type,emulsifier amount,particle size and distribution,temperature and viscosity were discussed in detail for controlling EW stability.Pointed out that the EW stability in long time has no inner link often between heat storage or cold storage and the normal temperature storage.The stability of EW through time is important guarantee of two year shelf life.The grain-size distribution meter and versatile stable analyzer may be used for dertermining EW stability.