Studies On The Preparation And Performances Of Abamectin And Tebuconazole Microcapsule Suspensions

Controlled-release technology has been applied in the pesticide industry for decades.Controlled-release formulation has many advantages such as long efficacy duration,application security,low toxicity,environmental-friendly,and so on.It will be an important development direction in pesticide formulations processing in the future.Abamectin is easily degraded by ultraviolet radiation,and tebuconazole is liable to cause phytotoxicity to seeds.Controlled-release formulation preparations of them can avoid the problems.The formulations not only increase effective period of active ingredients,but also prevent side effects on seeds and crops.This paper studied the preparation conditions about 5% abamectin ureaformaldehyde microcapsule suspensions,5% abamectin melamine-formaldehyde microcapsule suspensions,5% tebuconazole urea-formaldehyde microcapsule suspensions and 5% tebuconazole melamine-formaldehyde microcapsule suspensions.The primary results were as follows:1.The experiment investigated the preparation process of urea-formaldehyde resin microcapsule suspensions.The effects such as the dosage of urea-formaldehyde resin,the kinds of emulsifiers,the dosage of emulsifiers and emulsifying time,emulsifying stir-speed,terminal pH,the interval time of acid adjustment were studied.Determined the mean diameter of the microcapsules,encapsulation ratio of the prepared microcapsule suspensions,we have obtained an optimal preparation process for preparing urea-formaldehyde resin microcapsule suspensions.The optimal preparation conditions were: the dosage of urea-formaldehyde resin in the preparation was 15%,emulsifier was SDS and the dosage was 2%,emulsifying time was 15 mins,emulsifying stir-speed was 1000r/min,terminal pH was 2,acid adjustment interval was 15 mins,and the solidifing temperature of the microcapsules with high encapsulation ratio was controlled at 70? for 105 mins.2.The experiment investigated the preparation process of melamine-formaldehyde resin microcapsule suspensions.The effects such as of the dosage of melamine-formaldehyde resin,the kinds of emulsifiers,the dosage of emulsifiers and emulsifying time,emulsifying stir-speed,terminal pH,the interval time of acid adjustment interval were studied.Determined the mean diameter of the microcapsules,encapsulation ratio of the prepared microcapsule suspensions,we have obtained an optimal preparation process for preparing melamine-formaldehyde resin microcapsule suspensions.The dosage of melamine-formaldehyde resin in the preparation was 15%,emulsifier was HEC and the dosage was 2%,emulsifying time was 15 mins,emulsifying stir-speed was 1000r/min,terminal pH was 4,acid adjustment interval was 25 mins,and the solidifing temperature of the microcapsules with high encapsulation ratio was controlled at 55? for 105 mins.3.The experiment investigated the optimal adjuvants for the preparation of the above microcapsule suspensions.According to relevant national standards and industry standards we chose the best pesticide adjuvants for the formulations.T-36 was chosen as a dispersant for the preparation of urea-formaldehyde resin microcapsule suspensions and the optimizing dosage was 3%.T208 was chosen as a thickening agent and the optimizing dosage was 1%.Ethylene glycol was chosen as a antifreezing agent and the optimizing dosage was 4%.SDBS was chosen as a dispersant for the preparation of melamine-formaldehyde resin microcapsule suspensions and the optimizing dosage was 3%.The thickening agent and antifreezing agent were as same as preparation of urea-formaldehyde resin microcapsule suspensions.4.The release properties of the microcapsule suspensions using two different wall materials in aqueous solution were measured.The results showed that the microcapsule suspensions exhibited good sustained release effects,and melamine-formaldehyde resin microcapsule suspensions demonstrated better sustained release effects.