Synthesis and Characterization of Microcapsules with Chlorpyrifos Cores and Polyurea Walls1

Microcapsules with chlorpyrifos cores and polyurea walls were synthesized with 2,4-tolylene diisocyanate as an oil-soluble monomer and ethylenediamine as a water-soluble monomer via an interfacial polycondensation reaction. The products were characterized by means of Fourier transform infrared spectrometry, 13C NMR spectrometry and 31P NMR spectrometry. The morphology, the particle size and the particle size distribution, and the thermal properties were also evaluated. The prepared microcapsules exhibit clear and smooth surfaces and have a mean diameter of 28. 13 μm. These microcapsules also have a good thermal stability for long-term use, and have potential applications in minimizing the toxicity of chlorpyrifos through controlled release.