Preparation method of pirimicarb microcapsules

Abstract

The invention discloses a preparation method of pirimicarb microcapsules. The preparation method comprises the following steps: (1) carrier preparation: performing a polymerization reaction of succinic acid, butanediol and lactic acid in a molar ratio of 1:1:(0.2-0.3) to obtain a carrier PBS-co-PLA; (2) oil phase preparation: weighing the components PBS-co-PLA, pirimicarb and dichloromethane in a mass ratio of (3.5-4.5):1:10; dissolving the carrier PBS-co-PLA in dichloromethane; and after complete dissolution, adding pirimicarb raw medicine and dissolving to obtain an oil phase; (3) water phase preparation: weighing deionized water in a mass ratio of a water phase to the oil phase being (5-7):1, adding an emulsifier and a dispersing agent and dissolving to obtain the water phase; and (4) microcapsule preparation: adding the oil phase into the water phase to obtain an oil-water mixed emulsion; adding an antifoaming agent and curing to obtain a microcapsule suspension; and washing and removing the supernate and drying to obtain a finished product. The method is simple in technology and environmentally friendly. The obtained pirimicarb microcapsules have relatively good form, the encapsulation efficiency reaches 78%, the pesticide loading capacity is up to 50%, the effective release period is 30 days, the pesticide release amount is 94%, and thus the pirimicarb microcapsules are an ideal pesticide slow-release agent.

Description

technical field [0001] The invention belongs to the technical field of pesticide preparation, and in particular relates to a preparation method of pirimicarb microcapsules. Background technique [0002] Pirimicarb is a moderately toxic insecticide. No irritation to eyes and skin, no chronic toxicity, low toxicity to fish, bees and birds, safe to natural enemies of aphids. It has contact killing, fumigation and foliar penetration effects. It is a highly selective aphidicide, which can effectively control all aphids except cotton aphid, and is also effective for aphids resistant to organophosphate. Rapid insecticide, but short residual period. It is safe for crops and does not harm natural enemies. It is an ideal agent for comprehensive control. It is suitable for controlling aphids on vegetables, tobacco and food crops. [0003] Microcapsules (Microcapsules, MC) are a kind of active substances (in pesticides, original drugs) that use natural or synthetic polymers or some...

AI Technical Summary

Problems solved by technology

Since then, the research and development of microcapsules has carried out a lot of basic research in agriculture, and has made some progress. At present, more than 200 agrochemical companies are conducting research on the development and application of microcapsules. It has a history of more than 40 years, but compared with the field of pharmaceutical microcapsules, its development is relatively slow. At present, there are few commercialized pesticide microcapsules.

[0006] The methods of pesticide microencapsulation mainly include interfacial polymerization method, condensed phase separation method, in-situ polymerization method, solvent evaporation method, etc., and these methods are not only complicated in process and high in cost, but also use a large amount of organic solvents, polluting the environment