Kefeng Xiao

Study on Preparation of Abamectin Microcapsule with Interfacial Polymerization

The abamectin was microencapsulated with interfacial polymerization. The bursa wall materials of Abamectin microcapsule used in the experiment was polyurea which was produced by Tolylene-2,4-diisocyanate (TDI) and hexamethylenetetramine. The stirring speed and the dosage of emulsifier were determined by preliminary experiments, and the technical conditions for abamectin microencapsulation were optimized by orthogonal experiment, meanwhile, the optimal proportion and dosage of bursa wall materials, solvent and dispersant were determined. Encapsulation efficiency was measured by UV spectrophotometer. Results show that the encapsulation efficiency of microcapsules obtained is up to 90%.

Screening of Additives for 1% Abamectin Microcapsules Suspension

Suitable additives for 1% abamectin microcapsules suspension were screened in this paper. Results show that Sodium dodecyl sulfate and NNO are suitable wetting and dispersing agent, xanthan gum act better than other four reagents as thickener, and 3% ethylene glycol is better than glycerol as antifreeze. The determination of suitable additives lays a solid foundation for the preparation of 1% abamectin microcapsules suspension.

Screening of Additives for Preparing 5% Toltrazuril Suspension Concentrate

Suitable additives are the essential parts of 5% toltrazuril suspension concentrate. This paper mainly focused on screening additives for preparing 5% toltrazuril suspension concentrate. Results show that xanthan gum is a suitable suspending agent, 1,2-propanediol is optimal wetting agent, and citric acid act excellently as flocculant.

Cefquinome Controlled Size Submicron Particles Precipitation by SEDS Process Using Annular Gap Nozzle

An annular gap nozzle was applied in solution enhanced dispersion by supercritical fluids (SEDS) process to prepare cefquinome controlled size submicron particles so as to enhance their efficacy. Analysis results of orthogonal experiments indicated that the concentration of solution was the primary factor to affect particle sizes in SEDS process, and feeding speed of solution, precipitation pressure, and precipitation temperature ranked second to fourth. Meanwhile, the optimal operating conditions were that solution concentration was 100 mg/mL, feeding speed was 9 mL/min, precipitation pressure was 10 MPa, and precipitation temperature was 316 K. The confirmatory experiment showed that of processed cefquinome particles in optimal operating conditions was 0.73 μm. Moreover, univariate effect analysis showed that the cefquinome particle size increased with the increase of concentration of the solution or precipitation pressure but decreased with the increase of solution feeding speed. When precipitation temperature increased, the cefquinome particle size showed highest point. Moreover, characterization of processed cefquinome particles was analyzed by SEM, FT-IR, and XRD. Analysis results indicated that the surface appearance of processed cefquinome particles was flakes. The chemical structure of processed cefquinome particles was not changed, and the crystallinity of processed cefquinome particles was a little lower than that of raw cefquinome particles.

Optimization of Synthesis of 2-Ethoxy-4-Nitrophenol

This paper presents the synthesis of 2-ethoxy-4-nitrophenol using three types of nitrification synthesis schemes with 2-ethoxyphenol as main reactant. The comparison of the reaction conditions, reaction time, the quantity of the reaction byproducts, yield and post-treatment of the reaction product among these three synthesis schemes is made. It concludes that Ferric nitrate is the optimal catalyst for nitrification. Finally, melting point test and infrared characterization were conducted for the products. It shows that the product contains 2-ethoxy-4-nitrophenol and the yield is 55.48%.

Optimization of Formulation of 5% Toltrazuril Suspension Concentrate and Enhancement of its Bioavailability in Material Engineering

Suitable additives for preparing 5% toltrazuril suspension concentrate are screened. And optimal formulation of 5% toltrazuril suspension concentrate was determined as follow: the proportion of toltrazuril is 5%, Xanthan gum 0.3%, 1,2-Propanediol 10.0%, Citric acid 0.6% and the remainder is water. The pH value of that is 7.0. Thereby, the bioavailability of toltrazuril is improved.

Optimization of Formulations of 1% Abamectin Microcapsule Suspensions with Properties of Biochemical Materials

By orthogonal experiments, optimal formulation of 1% abamectin microcapsule suspensions was determined as follow: the proportion of abamectin microcapsule is 1%, NNO 5.0%, sodium dodecyl sulfate 3.0%, xanthan gum 0.3%, ethylene glycol 3%, and the remainder is water. The indicators of the formulation are all excellent: good dispersibility, suspension rate greater than 90%, cold storage and hot storage syneresis rates under 5%. The properties of biochemical materials were used in optimization. The optimal formulation provides an experimental basis for industrial production of abamectin microcapsule suspensions.