Preparation and characterization of 2,4-D butyl ester capsule suspension for mitigation its drift risk

A novel capsule suspension (CS) formulation was prepared by in situ polymerization of melamine formaldehyde (MF) resin which was the first time to be used to encapsulate 2,4-D butyl ester. The prepared 2,4-D butyl ester capsule suspensions were studied by ultraviolet spectrophotometer (UV), laser particle size analyzer, Optical microscopy (OM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Results showed that the encapsulation efficiency reached 93.23%, and the mean particle size (D-50) could be reduced to 13.80 mu m by adding 4% Tween80. OM and SEM images illustrated that the core-shell structure related largely to the stability of emulsion. The spherical microcapsules possessed with rougher outer surface and the shell was about 1.5-2.0 mu m thick with good methanol tolerance. Then, the formation of pre-polymer, shell material and microcapsules were revealed by FT-IR. Finally, experiments showed that the 2,4-D butyl ester CS exhibited a sustained releasing behavior in water, which could reach to 14 days.