纳米Al_2O_3改性三聚氰胺-脲醛自修复微胶囊的制备及应用

Preparation and Application of Melamine-urea-formaldehyde Self-healing Microcapsules Modified by Nano-Al_2O_3

以纳米Al_2O_3改性三聚氰胺-脲醛树脂(MUF)为壁材,环氧树脂为芯材,采用原位聚合法合成了微胶囊,并采用光学显微镜(OM)、扫描电子显微镜(SEM)、红外光谱仪(FTIR)、X射线光电子能谱分析仪(XPS)、热重分析仪(TGA)等对其表面形貌、结构及热性能等进行了表征和测试;将改性后的微胶囊加入自修复环氧树脂涂层中,并对其热性能、力学性能、自修复性能及电化学性能进行测试。结果表明,当芯壁比为1.5:1、纳米Al_2O_3质量分数为4.5%时,纳米Al_2O_3在壁材中均匀分布,微胶囊的表面粗糙度和热稳定性均增加。当涂层中改性微胶囊质量分数为5%时,涂层的热稳定性提高,且涂层的拉伸强度、弯曲强度、冲击强度及粘结强度分别提高了111.9%、55.1%、10.6%和51.9%;制备的涂层具备较好的自修复性能;涂层的耐腐蚀性能随着微胶囊质量分数的增大而增强。

Microcapsules were synthesized by in-situ polymerization with MUF resin modified by nano-Al2O3 as wall material and epoxy resin as the core material. The morphology, structure and thermal properties of the microcapsules were characterized by optical microscope（OM）, scanning electron microscope（SEM）, fourier transform infrared spectroscopy （FTIR）, X-ray photoelectron spectroscopy（XPS） and thermo gravimetric analysis （TGA）. The microcapsules were applied to the epoxy resin matrix to prepare self-repair coating. The thermal property, mechanical properties, self-healing property and the electrochemical property of the coating were investigated. The results show that, when the core/wall ratio is 1.5∶1 and the content of nano-Al2O3 is 4.5%, nano-Al2O3 is evenly distributed in the wall. The surface roughness and the thermal stability of microcapsules increase. When the microcapsules content is 5%, the thermal stability of the coating increases. The tensile strength, the bending strength, the impact strength and the bonding strength of the coating increase by 111.9%, 55.1%, 10.6% and 51.9%, respectively. The coating possesses good self-healing performance. The corrosion resistance of the coating increases with the increase of the microcapsule content.