The Preparation Of Microcapsules Formulations Of Imidacloprid

In this study,the application of interfacial polymerization for microcapsules are researched.In the course,MMA studied as the wall meterial meanwhile BPO and NaHSO3 as initiators.We identifiedthe formulation of 10%imidacloprid MC by changing the amount of MMA,BPO and NaHSO3.The formulation as follows:MMA6.4%,BPO 0.25%,NaHSO30.1%,emulsifier A 9.6%.The surface morphology of microcapsules Shows that:the severe temperature changes from Polycondensation often leads to the surface morphology of microcapsules worse;The low reaction temperature needs a long reaction time;and if reaction temperature is too high,it appears likely to cause agglomeration.Therefore,this study chose polycondensation reaction temperature is 30℃.Stirring speed could make great impact on the surface morphology of microcapsules, too.By analysis the results,150 r/min was choiced as the stirring speed.Additional mechanical force would damage the microcapsules,so the polycondensation time on the formulation of microcapsules also have a role.This research by studying the final choices of polycondensation time 24 h.On the basis of the 10% imidacloprid MC studied,Toxicity measurement are studied on cotton aphid by using it.10% Imidacloprid MC and 10% imidacloprid WP on cotton aphid toxicity regression equations were got,as follows:Y=0.7751X-2.0048 and Y=0.7845-1.4377,LD50 are 3.23 and 2.47 mg/L.By the results,10% Imidacloprid MC have a worse quick result than 10% imidacloprid WP.In the field efficacy trials,we found 10% Imidacloprid MC have a longer persistence than 10% imidacloprid WP on cotton aphids.In the 24 days after treatment,30g a.i./hm2 still had a control effect as 80.53%.so the pesticide imidacloprid after the microcapsules can effectively extend its control effect on cotton aphid.It had a certain significance on mitigation aphid huzard. After the study,we found that the pesticide had a lower destruction on cotton lacewings and ladybirds after the microencapsulation of pesticides treated and no apparent injury on cotton.On the basis of 10%imidacloprid MC,we got the formulation of 12.5% imidacloprid?Cyhalothrin MS by studing on emulsifier type,proportion and amount,type and amount of dispersant,water hardness and acidity,stirring speed and so on.And we also solved the problem of agglomerate by researching the kinds and amounts of dispersant.The final conditions of 12.5%imidacloprid?Cyhalothrin MS as follows: EmulsifierB:C=9:1,10%;dispersant B of 4%,PH=7,mixing speed 300 r/min and stirring time 0.5 h after cyhalothrin was into.On the basis of 12.5%imidacloprid?Cyhalothrin MS,efficacy in field trials was Applicated on the cotton mirids.The experiment showed that 12.5% imidacloprid? cyhalothrin MS had a better quick result and its maintained a long period of time on cotton mirids.It had a quiet effective with 10%Fipronil MC.By the research,we found the 12.5% imidacloprid?cyhalothrin MS had a lower toxicity than 12.5% imidacloprid? cyhalothrin SL in the same concentration.