【作者】 薛背背；

【导师】 路福绥；

【作者基本信息】 山东农业大学 ， 应用化学， 2011， 硕士

【摘要】 随着人们环保意识的增强,以环境友好和成本低廉的水基性制剂代替有机溶剂为载体的乳油已成为人们关注的焦点。农药水悬浮剂以其高效安全、环境相容性好等优点,成为农药新剂型的发展方向之一。目前制备农药水悬浮剂的方法大都是从分散的角度出发采用机械粉碎的方法来制备,本实验从凝聚的角度出发采用溶剂替换法对氟铃脲水悬浮剂的制备进行了研究。在筛选合适的溶剂及润湿分散剂的基础上,对氟铃脲水悬浮剂有效成分含量对其水悬浮剂制备的影响进行了系统地研究,同时研究了电解质等对氟铃脲水悬浮剂稳定性的影响,以期为农药水悬浮剂的开发提供依据。本论文主要进行了以下几个方面的研究:1、采用溶剂替换法制备了氟铃脲水悬浮剂,通过测定氟铃脲水悬浮剂颗粒的平均粒径Dav及颗粒界面的Zeta电势,对1%的氟铃脲水悬浮剂的溶剂及润湿分散剂进行了筛选,确定了其溶剂为丙酮,丙酮与有效成分的质量比为10:1;润湿分散剂为:MOTAS与700#的复配体系,其质量比为1:1,MOTAS用量为1.25%时氟铃脲水悬浮剂的稳定性最好;有机相中乙醇的添加可以显著提高氟铃脲水悬浮剂的分散稳定性,有机相中乙醇的加入量增加到31.2%时体系的分散稳定性达到最好。2、氟铃脲水悬浮剂有效成分含量影响乳滴的形成,随着有效成分含量的增加,颗粒的平均粒径逐渐增大,颗粒界面的Zeta电势的绝对值先增大后减小;在选择合适的溶剂及润湿分散剂的基础上进行了单因素实验,研究了搅拌速度、搅拌时间、滴加速度、温度对氟铃脲水悬浮剂颗粒的平均粒径的影响,结果表明均不同程度的影响着颗粒的平均粒径,确定其搅拌速度:300r/min,搅拌时间:30min,滴加速度:1ml/min,温度:室温;对分散剂用量、丙酮乙醇的比例、有机溶剂的量及油水相体积比进行了正交实验,发现有机溶剂的量对氟铃脲水悬浮剂颗粒的平均粒径的影响最大,远远的大于其他因素对氟铃脲水悬浮剂颗粒的平均粒径的影响。通过提高有机溶剂的量明显的降低了氟铃脲水悬浮剂颗粒的平均粒径,将有效成分的含量由1%提高到6%,有效的节约了生产成本。3、以1%的氟铃脲水悬浮剂为研究对象研究了电解质对Zeta电势的影响,结果表明:氟铃脲水悬浮剂颗粒界面的Zeta电势在实验pH范围内均为负值,pH影响分散剂在水中的解离,随着pH的增加,颗粒界面的Zeta电势的绝对值先增加后减小,在pH为8.39左右颗粒界面Zeta电势的绝对值最大;电解质的种类及浓度均影响氟铃脲水悬浮剂的Zeta电势,随着MgCl2和NaCl浓度的增加Zeta电势的绝对值降低,且MgCl₂对体系的影响更为显著。更多还原

【Abstract】 With the increasing awareness to protect the environment, we have focused on the environment friendly and low-cost water-based formulation instead of the Emulsifying Concentrate with organic solvents. Suspension Concentrate (SC) has become one of the development directions of new pesticide formulation which is efficient and safe, and has good environmental compatibility et al. Now the method of preparation of SC mostly was mechanical grinding. In this paper, the preparation of Hexaflumuron SC was researched by solvent replacement from condensation. On the basic of the selection of suitable solvent and the wetting and dispersing agents, the influence of the active ingredient content on preparation was systematically studied. Zeta potential of the system which was influenced by the electrolyte was also studied. We hoped that it could provide a theoretical basis for the development of SC. This paper mainly studied from the following aspects:1. We screened the solvent and the wetting and dispersing agents of 1% Hexaflumuron SC which produced by a solvent displacement technique by means of measuring average size and Zeta potential analysis. Determining acetone as its solvent, the mass ratio of acetone and the active ingredients was 10:1. Wetting and dispersing agents was: MOTAS and 700 #, and the mass ratio of MOTAS and 700# was 1:1. When the mass fraction of MOTAS was 1.25%, the stability of Hexaflumuron SC was best. The dispersion stability of Hexaflumuron SC could be largely enhanced when the ethanol was added. The dispersion stability attained best near 31.2% of the mass fraction of ethanol.2. The content of the active ingredient of Hexaflumuron SC influenced the formation of emulsion droplet. With the content of active ingredient increasing, the average particle size increased, the absolute value of Zeta potential of particles first increased and then decreased, and dispersion stability reduced. On the basic of select suitable solvents, wetting and dispersing agents, we carried out a single factor experiment. We studied the influence of the stirring speed, stirring time, dropping rate and temperature on the average size of particles of Hexaflumuron SC. The results showed that all above factors affected the average size of the particles and then determined the stirring speed: 300r/min, stirring time: 30min, dropping rate: 1ml/min, temperature: room temperature. On the basic of previous experiments, we found that the concentration of organic solvent which effected average size of hexaflumuron SC particles had the largest influence, far greater than other factors. By increasing the concentration of organic solvent could significantly reduce the average size of Hexaflumuron SC particles. The concentration of active ingredient increased from 1% to 6%, effectively saving the cost of production.3. Take 1% hexaflumuron water suspension as the research object, this paper studied the influence of the electrolyte on Zeta potential. The results showed that Zeta potential of hexaflumuron SC were negative within the experimental pH values. pH affected the dissociation of dispersant in water. With the increaseing of pH, the absolute value of Zeta potential first increased and then decreased. When the pH was about 8.39, the absolute value of Zeta potential is maximum. The type and concentration of salt ions affected the Zeta potential of hexaflumuron SC. With the increasing of the concentration of MgCl2 and NaCl, the absolute value of Zeta potential decreased, and the impact of MgCl2 on the system was even more significant.更多还原