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In the development of the embedded microspheres concept for self-healing coating,the preparation of microcapsules has been paid more attentions.A new series of microcapsules were prepared by in situ polymerization technology in an oil-in-water emulsion with polyoxyrnethylene urea (PMU) as a shell material and a mixture of epoxy resins (diglycidyl ether of bisphenol A:DGEBPA) and 1-butyl glycidyl ether (BGE) as core materials.The PMU microcapsules were characterized by Fourier transform infrared spectroscopy (FTIR),scanning electronic microscopy (SEM),optical microscope (OM),differemial scanning calorimeter (DSC) and thermo gravimetric analyzer (TGA) to investigate their chemical structure,surface morphology,size distribution and thermal stability,respectively.The results indicate that PMU microcapsules containing epoxy resins can be synthesized successfully.The optimized reaction parameters were obtained as follow:agitation rate 700 rpm,60℃ water bath,pH=3.5,core material 20ml and hot water dilution by in-situ polymerization.The size is around 100 μm.The dispersed and integrated microcapsules with 70% core content and 79% yield can be produced using above parameters.The rough outer surface of micrecapsule is composed of agglomerated PMU nanoparticles.The size and surface morphology of miorocapsule can be controlled by selecting different processing parameters.The microcapsules basically exhibit good storage stability at room temperature,and they are chemically stable before the heating temperature is up to approximately 200℃.Growth of coating damage at the scribe was arrested in self-healing coatings with all microcapsule formulations compared to control samples.The core constituents of self-healing microcapsules are released when the microcapsules are raptured by damage to the coating in which they are contained,whether from natural cracks resulting from aging or from mechanical damage to the coating.The microcapsules exhibit long-term stability in dried paint films,they retain their core materials,and release them only when they are ruptured.