含环氧树脂微胶囊自修复涂层的制备及其性能

Preparation and Properties of Self-healing Coatings Containing Epoxy Resin Microcapsules

目的制备含环氧树脂微胶囊的二元自修复涂层,并对其力学性能和自修复性能进行研究。方法将自制环氧树脂E-51/三聚氰胺-脲醛树脂微胶囊和潜伏型固化剂(2-甲基咪唑)按一定比例添加到环氧树脂基体中,制备二元自修复环氧树脂涂层。利用漆膜弹性试验机、漆膜冲击试验机和万能拉伸试验机对涂层的弯曲性能、耐冲击性能和拉伸性能进行测试。利用扫描电子显微镜(SEM)、光学显微镜(OM)对涂层的自修复性能进行考察。采用EIS对涂层的电化学性能进行测试。结果成功制备了含环氧树脂微胶囊二元自修复涂层,当涂层中微胶囊的质量分数为3%时,涂层的冲击强度和拉伸强度分别提高了10.6%和14.6%。当涂层中2-甲基咪唑和微胶囊质量分数分别为6%和5%时,涂层的自修复性能较佳。当微胶囊质量分数为9%时,涂层的电化学阻抗值可达1.2×105?。结论微胶囊的加入可有效提高涂层的冲击强度和拉伸强度。随着涂层中潜伏型固化剂含量的增大,涂层的自修复性能增强。当潜伏型固化剂含量达到一定值时,涂层的自修复性能随着微胶囊含量的增大而增强。随着微胶囊含量的增加,涂层的电化学阻抗值增大。

The work aims to prepare binary self-healing coating containing epoxy resin microcapsules and study mechanical properties self-healing property of the coating. The binary self-healing epoxy coating was prepared by adding self-made epoxy resin E-51/urea-melamine-formaldehyde microcapsules and latent curing agent（2-methylimidazole） to epoxy resin matrix in certain proportion. Bending property, impact resistance and tensile strength of the coating were tested with paint film elasticity testing machine, paint film impact testing machine and universal tensile testing machine. Self-healing property of the coating was investigated with OM and SEM. Electrochemical property was tested with EIS. The binary self-healing coating containing epoxy resin microcapsules was successfully prepared. When the microcapsules content in the coating reached 3%, the impact strength and tensile strength of the coating increased by 10.6% and 14.6%, respectively. When the 2-methylimidazole and microcapsules content was 6% and 5%, respectively, the self-healing property of the coating was excellent. When the microcapsules content in the coating was 9%, electrochemical impedance value of the coating was up to 1.2×105 ohms. The addition of microcapsules can effectively improve the impact strength and tensile strength of the coating. As the content of latent curing agent increases in the coating, the self-healing property of the coating gradually improves. When the content of latent curing agent reaches a certain value, the self-healing property of the coating improves as the microcapsules content increases in the coating. The electrochemical impedance value of the coating increases with the increase of microcapsules content.