Research Into The Influence Of Surface Modified Epoxy Microcapsule Force On Performance Of Self-healing Coating

In the process of using polymer coating,there will be some micro cracks,the continuous generation and collection of micro cracks will eventually lead to cracking or breakage of the micro cracks,so that the mechanical properties and protective properties of the coating are greatly damaged,and it is difficult to repair the internal micro cracks by the existing means.In order to solve this problem,s self-healing coatings came into being.Self-healing coating has a certain self-healing function,and it has the function of automatic repair of micro cracks in the coating.Aldehyde epoxy resin polyurea microcapsules mixed repairing agent dispersed in a resin matrix,when the micro cracks in the coating,the extension of micro cracks will cause the occurrence of micro cracks,thereby releasing the repair agent,the repairing agent is filled with micro cracks under the action of the siphon,and the micro cracks are repaired,the mechanical properties,corrosion resistance and appearance of the mechanical properties were recovered to some extent.This article choose polyurea aldehyde as the capsule wall,E-51 epoxy resin as microcapsule core,microcapsules of epoxy resin self-healing coatings were prepared by in situ polymerization,and the surface of microcapsule was modified by silane coupling agent KH-550.Morphology analysis showed that the prepared microcapsules have good spherical degree,the average wall thickness of microcapsules is about 2-5?m.Particle size analysis showed that distribution of particle size distribution of microcapsules and the particle size of the microcapsules showed a trend of linear decrease with the increase of the mixing rate.When the stirring rate is 400r/min,the size of the prepared microcapsules is 80?m,wall thickness is 3?m.The core content of microcapsules increased with the increase of particle size.Using infrared spectroscopy studies the composition of micro capsule,and prove of the prepared microcapsules is coated with polyurea formaldehyde epoxy resin microcapsule.The sealing performance of microcapsules was studied by immersion test,results showed that the larger the size of micro capsules,the better the sealing performance.Thermal stability of microcapsules was studied by thermogravimetric analysis,results showed that the microcapsules maintain good thermal stability below 200?.Self-healing coatings were prepared by using ordinary microcapsule and after surface modification treatment of microcapsules.Experimental results show that the addition of microcapsules to some extent reduce the adhesion between the coating layer,flexibility and impact resistance.For ordinary microcapsules,the optimum adding particle size is 80?m,and the optimum adding amount to 20wt%.If we can modified the surface of microcapsules,the adhesion between the coating layer will promote 10% ~ 30%,the amount of microcapsules can be up to 25wt%,the flexibility of the coating will raise a level,the shock resistance of coating will promote 3% ~ 30%.Through the research of macroscopic corrosion morphology and electrochemical ac impedance technology,we can find that,the cracks in coating can break microcapsule,and repair agent will fill the cracks,enhance the corrosion resistant properties of the coating,so that make coatings have self-healing capability.The self-healing properties of coating will enhancement along with the increase of content in microcapsules.For the self-healing coatings add with same content of microcapsule,the surface f microcapsules were modified can improve the corrosion resistance of coating.The impedance of the coating with microcapsules first increased and then decreased in the process of soaking.All in all,the microcapsules can repair the resistance of self-healing coating.