农药水乳剂稳定性研究

Study on the Stability of Pesticide Aqueous Emulsion

试验和试验样品检测数据充分说明了水乳剂分散体系的平均粒径和制剂稳定性与水乳乳化剂的品种和用量有密切的关系,而与制备时剪切输入的能量多少关系不大。乳化剂的选择是生产合格水乳剂的关键。在配制水乳剂时,要根据合格水乳剂需要而确定表面活性剂(乳化剂)的量,同时也要考虑水乳剂被喷洒使用时对靶标的润湿、展着、覆盖和附着等因素的影响。使用液体农药或低熔点农药制备水乳剂时应经过试验确定溶剂的加入量,以保证制剂分散效果和稳定性。水乳剂被稀释时入水自然扩散性(初乳化状态)与制剂黏度有关,与制剂的稳定性和平均粒径没有直接关系,所以不能像乳油那样用入水自然扩散情况评价水乳剂的乳化分散情况和内在质量。

This paper through experiments and the test results, demonstrated that the average grain diameter and the emulsion stability have related to the varieties and the quantities of the emulsifiers, and have little related to the energy input. It is pivotal to choose a right emulsifier for a qualified EW. The quantity of emulsifier depends on not only the processing, but also wetting, spread, cover, attachment and field efficacy, etc. If liquid pesticides or low melting point pesticides are used to produce EW, the quantifies of the solution should be determined by the testing results to ensure the dispersibility and stability. When it＇ is diluted, the spontaneity of dispersion in water can be influenced by viscosity of formulation, and can not be influenced by stability and average grain diameter directly. So, the dispersibility and the intrinsic quality can not be estimated by the spontaneity of dispersion in water just like estimating the quality of EC.