聚羧酸盐分散剂在农药水悬浮剂中的应用及作用机理分析  

Application and mechanism of poly-carboxylate dispersant in suspension concentrate

作　　者：桂奇峰 张博[1] 张树鹏[1] 任天瑞[1] 

机构地区：[1]资源化学教育部重点实验室,植物种质资源开发中心,上海师范大学生命环境与科学学院,上海200234

出　　处：《中国科学：化学》2016年第11期1242-1248,共7页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(编号:21172147);"十二五"国家高技术研究发展计划(编号:2011AA100503)资助项目

摘　　要：聚羧酸盐分散剂具有独特的分散性能,可显著提高农药水悬浮剂等剂型的稳定性.本文应用3种聚羧酸盐分散剂分别制备了3种农药水悬浮剂,研究了聚羧酸盐分散剂在原药颗粒表面的吸附特征和吸附热力学,研究了聚羧酸盐分散剂对农药水悬浮体系Zeta电势和流变性质的影响,并分析了体系在热贮前后各稳定性参数的变化,最终得到了具有长期储存稳定性的农药水悬浮剂产品.研究结果显示,聚羧酸盐分散剂在原药颗粒表面的吸附符合Langmuir单分子层吸附模型,其中吸附热力学参数?G_(ad)<0、?S_(ad)>0、?H_(ad)<0且|?H_(ad)|<40 kJ mol^(-1),表明该吸附为自发进行的、放热、熵增的物理吸附过程.聚羧酸盐分散剂通过提高悬浮体系的Zeta电势,使得分散粒子间相互排斥,改善了体系的流动性能,从而提高农药水悬浮剂产品的长期储存稳定性.Polycarboxylate dispersants have unique dispersion properties, which can significantly improve the stability of suspension concentrate and other pesticide formulation. In this paper, we prepared three different suspension concentrates by three different polycarboxylate dispersants, respectively. The adsorption characteristics and absorption thermodynamics of poly-carboxylate dispersants onto azoxystrobin particle surfaces were studied. Meanwhile, the effect of poly-carboxylate dispersant on Zeta-potential and rheological property of suspension concentrates were investigated. Results show that the adsorption experiment data fit the Langmuir monolayer adsorption model well. The thermodynamic parameters are as follows： △G_（ad）0, △S_（ad）0, △H_（ad）0 and ｜△H_（ad）｜40 k J mol-1, indicating that the adsorption is a spontaneous exothermic physical process. By improving the Zeta potential of the suspension system, polycarboxylate dispersants can increase the mutual repulsion between the disperse particles and improve the flow property of system, thus enhancing the long-term storage stability of the suspension concentrates.

关 键 词：聚羧酸盐分散剂 农药水悬浮剂 吸附热力学 Zeta电势 

分 类 号：TQ450.6[化学工程—农药化工]