Effects Of Pesticide Adjuvants On Water Dispersible Granules Of Different Granulation Process

Water dispersible granules(WG) is known as dry suspending agent. It has become one of the most efficient and environmentally friendly pesticide formulation because of its convenience for package and transportation, dustless nonsolvent and safety. Extrusion WG has the performances of high density, poor disintegrability and dispersion while the high-speed mixed WG has rough surface, low strength characteristics, the differences between them lead to different application properties. The WG was composed of pesticide and additive. The applied properties(such as suspension rate, wettability and disintegrability) are mainly determined by dispersing agents, wetting agents and disintegrating agents. These are the focus of the formulation screening. There for, it can provide direction for the different process screening research of WG formula by studying on the different performance of additives in the process of extrusion granulation and high speed mixed granulation.Ultrafiltration liquid waste is obtained from the alkaline pulping black liquor through ultrafiltration. Owing to low lignin content, vast sugars and inorganic impurities, It is valueless and makes enormous waste of resources. There for,it can not only enlarge the selection range of WG additives, but also promote the efficient use of resources and reduce environmental pollution by applying the ultrafiltration liquid to WG formula.In this dissertation, the effects of the amount of water, extrusion granulation speed, mesh size, drying time, drying temperature on the extrusion WG properties and suspension particle size were researched firstly. the optimum condition was 20% water, 50r/min of the rotational speed, 0.6mm to 1.5mm of mesh size, 50 ℃ of the drying temperature, 50 min of drying time.The effect of different pesticide adjuvant on the extrusion WG and high speed mixing WG was studied. The results showed that, the surface area of WG made by extrusion was smaller than the high-speed mixing WG and the particles were more dense, so that extrusion WG was more difficult to wet, disintegration and dispersion.The suspension rate of extrusion WG is restrained obviously,, even those quality dispersants(such as polycarboxylic acid dispersants, naphthalene dispersants), were not functional. The effect of dispersants on the high-speed mixing WG was more obvious, it would be simplified when screening the dispersant. After dispersant compound with wetting agent, the suspension rate of two kinds of WG was greatly improved, while compound with disintegrants may promote or reduce the suspension rate of two kinds of WG so it was very important to select the appropriate disintegrant. Effects of different wetting agents in the extrusion WG were more obvious, so wetting agent require careful screening. Relatively, the high speed mixing WG was easy wetting, general wetting agent can achieve good wetting. The disintegrants produced the the same effect on the disintegrability of two kinds WG, the disintegrants can be employed universally on two kins of WG.Ultrafiltration waste liquid was the alkaline pulping black liquor treated by 2500 DA ultrafiltration membrane. It contains 5.67%lignin, 55.13% inorganic salt, 39.20% sugar content. The lignin ultrafiltration waste acted as 50% Pymetrozine WG additives. The results showed that the ultrafiltration waste liquid could be used as the binder and the disintegration agent of WG. When ultrafiltration waste was used as dispersing agent, with the increase of the amount, the particle proportion of 0.45mm-0.9mm particle size increased, better wettability and worse disintegration,but there was no good dispersion compared with lignosulfonate. Compared with other binders with the same content, the adverse effect of ultrafiltration on WG suspension was smaller, and the positive effect of the particle size of the WG was more than that of xylose, carboxymethyl cellulose and starch. In pymetrozine WG, the ultrafiltration waste disintegrating excellent, but the suspension rate, disintegrating and disintegrating particle size may be adversely affected.