Synthesis And Application Of The Materias To Controlled Release Of Avermectin Mocular

Avermectin(Av)is a high efficient macrolide insecticide and acaricide.However,its photo-oxidation,poor light stability,and short half-life advantages which limited its furthe use.During the progress in specific use,a variety of factors will cause the extremely low actual utilization rate.Based on these,the paper synthesize various functional carrier to encapsule avermectin,which aimed to improve the utilization efficiency.Details are as follows:1.Summarize the pesticide controlled release technology and its classification in carrier materials.At the same time,this part will clarify the structure,properties,characteristics and research status of avermectin.then put forward our research subject.2.This paper synthesized three kinds of functional chitosan which containing phenol(PH),benzoic acid(BA),catechol(CA)group.Then using these functionalized chitosans to encapsulate avermectin(Av)via emulsion polymerization to form spherical nanoparticles with a diameter of about 400 nm,the drug loading rate were 59.6%.53.0%.and 78.0%,respectively’.At the same time,studied their slow-releasing property,UV shielding property,foliar retention and biological activity.The results show that these three kinds of carriers have approximate slow-releasing property and UV shielding property.It also proved that they can enhanced the ability of foliar retention,especially for the Av@CA-CS,which rerention rate can reach 57.0%and 29.6%on the cotton and rice foliage while avermectin only 6.1%and 1.1%,respectively.These nano drug carriers show excellent properties and potencial value.3.This paper synthesized a functionalization PF127,which was modified with catechol,through esterification reaction.Then utilizes its amphiphilic structure to encapsule avermectin via solvent evaporation(Av@PF127-CA).It can form spherical nanoparticles with a diameter of about 175 nm,the drug loading rate was 37%.Then studied the properties of controlled release,UV shielding,foliar retention and biological activity.The result shows that the Av@PF127-CA can be controlled release till to 108 h and has remarkable photoprotection of avermectin,that Av@.PF 127-CA only decomposed about 26%.As the aspect to foliar retention,combined to the data of contact angle and surface energy,Av@PF 127-CA can not only wet the foliage quickly,but also remain 67.9%and 32.4%avemectin on the cotton and rice while Av almost wash out.4.This paper synthesize a special surfactant which simultaneously contain catechol group and long alkyl chain that via reductive amination reaction,then use the 1H NMR and 13C NMR to confirm the structure.Utilize the solvent evaporation method to encapsulate avermectin(Av@CA-S)to prepare the drug-loaded micelle,then characterized drug loading rate,morphology and particle size by UV,TEM and DLS.Get the spherical nanoparticles with a diameter of about 102 nm,and the drug loading rate was 41%.Then the test of photodegration,foliar retention and biological activity results show that Av@CA-S only decomposed 32.3%in 164 h.Meanwhile,the adhension rate on cotton and rice can reach 71.2%and 32.5%.Under the concentration of 100 ppm,10 ppm,5 ppm,1 ppm,comparing to the biological activity of Av@CA-S and Av can draw the conclusion that Av@CA-S own the competable insecticide activity.This paper synthesize three kinds of carrier to encapsule avermectin,the results show that the properties of slow-releasing,UV shielding,foliar retention and biological activity were performed well.Comparing the materials,found that the functional chitosan carrier materials have the best drug-loaded rate and controlled release properties,while the PF127-CA owned the best photostability,the CA-S have the most excellent foliar retention property on rice and cotton.