Research On A Novel Nano-pesticide Formulation Based On Epoxy Camellia Oil Polymer

To develop a novel pesticidal formulation with higher quality is the most important way to increase the control efficiency of a pesticide,as well as to decrease application amount.The physical and chemical properties of pesticides can be dramatically changed by an efficient formulation of pesticides.In recent years,continuous breakthroughs in nano technology and new nano materials drive the research of renewable biomass nanomaterials as pesticide additives.Compared with traditional petroleum-based polymer nanomaterials,renewable biomass nanomaterials have more green characteristics and great application potential.In this study,the triglycerides in camellia oil were first modified into plant oil monomer with end-group double bond by amidation and esterification,and then further epoxidized into epoxy camellia oil monomer to synthesize epoxy camellia oil polymers with different degrees of polymerization.By adjusting the ratio of acrylic epoxy camellia oil and acrylamide epoxy camellia oil,plant oil-based polymers with different adhesion properties were developed as the carrier of nano pesticides.By means of nuclear magnetic resonance（NMR）,gel chromatograph（GPC）,thermogravimetric analysis（TGA）,differential scanning calorimeter（DSC）,the synthesis,thermal stability,adhesion,dispersion and particle size of polymer materials were studied.Nano-plant oil-based polymers（NPP）with good indexes were used to study the performance of pesticide carriers.Firstly,the pesticide embaryl salt（EB）was encapsulated with NPPs to formulate the EBM_50-50.Then,the retention rate and photodegradation rate of the pesticide coated by the NPP on tobacco leaves were determined under different precipitation.Finally,the toxicity test of the EBM_50-50 against Spodoptera litura to assess improvement of control efficiency.The main research results are as follows:1.The synthesis and processing technology of plant oil-based emulsion were determined.Acrylate epoxy camellia oil monomer（ECO）and acrylamide epoxy camellia oil monomer（ECO-NH）were prepared from camellia seed oil by continuous amidation,esterification and epoxidation,Then,a series of plant oil diblock copolymers(PEG₉₀-b-P(ECO_100-x-co-ECONH_x)s)were obtained by RAFT polymerization of the two monomers at different ratios,Seven polymers were successfully synthesized by NMR and gel chromatograph.The results of gel chromatography showed that the molecular weight of the copolymer was in the range of 1.18～1.51,and the average molecular weight was in the range of 20.7～29.7 k Da.2.The NPP with the best properties were screened.The particle size,thermal properties,adhesion properties and wettability of seven kinds of NPP were analyzed.It is found that PEG₉₀-b-P(ECO₅₀-co-ECONH₅₀)has the most balanced adhesion and cohesion.According to the result of rain erosion,the nano-pesticide EBM_50-50 showed the best adhesion property among the 7 NPPs with different mix proportions.3.It was confirmed that the NPP as the carrier of nano-pesticide could significantly improve the environmental stability of pesticide.The results showed that the residues of EBM_50-50 on tobacco leaves were significantly higher than those in EB group under different rain erosion conditions.An increasing precipitation,led to difference higher difference on residual pesticide.Under erosion of 36mm heavy precipitation,the residual amount of pesticides on the leaves of EBM_50-50treatment group was 50%higher than that of the control.The degradation experiments of EB under ultraviolet irradiation at different wavelengths showed that the nano-plant oil-based polymer had a certain buffering effect on EB degradation under the ultraviolet irradiation at 254 nm and 302 nm.The degradation rate of emamectin benzoate in EBM_50-50 was slightly slower than that of EB control,while the degradation rate of emamectin benzoate under the ultraviolet irradiation at 365 nm was significantly slower than the other two wavelengths.There was no significant difference between EB and EBM_50-50 photodegradation rates.4.The NPP as the carrier of nano-pesticide significantly improved the pest control effeciency under the condition of precipitation.Compared with EB,EBM_50-50 treatment significantly increased the mortality of S.litura larvae under different precipitation of 10mm,24 mm and 36 mm.Under 24mm precipitation,the larval mortality for EBM_50-50treatment reached 91.6%in 24 h,which was 48.3%higher than that of EB treatment.Under the condition of 36 mm precipitation,the larval mortality for EBM_50-50 treatment reached56.6%in 36h,which was 21.6%higher than that of EB treatment,and the lethal time was greatly shortened.At the same time,for the EBM_50-50 treatment,the larval feeding area of tobacco leaves was significantly lower than that of control under precipitation condition,the larval feeding area was reduced by 34%under 36mm precipitation.The results verified that the NPP as the carrier of nano-pesticide has a significant synergistic effect on the pesticide under the influence of natural precipitation environment.