环氧树脂-脲醛树脂@2-甲基咪唑微胶囊/环氧树脂复合材料的制备及自修复性能

以一步原位聚合法制备芯材为环氧树脂（E-51），壁材为脲醛树脂（UF）的E-51-UF微胶囊。采用FTIR、SEM、TG、粒度分析仪等分别对E-51-UF微胶囊结构、表面形貌、耐热性和粒径分布进行了表征。以E-51-UF微胶囊为核，固化剂2-甲基咪唑（2-MI）为壳通过共混复合，得到E-51-UF@2-MI复合微胶囊。将E-51-UF@2-MI微胶囊填充到E-51基体中，制备了E-51-UF@2-MI微胶囊/E-51复合材料拉伸试样、弯曲试样和梯形双悬臂梁（TDCB）修复试样，并采用电子万能试验机测试其性能。分析了填充E-51-UF@2-MI微胶囊质量分数对E-51-UF@2-MI微胶囊/E-51复合材料力学性能及自修复性能的影响。结果表明:制备的E-51-UF微胶囊呈现规整球形结构，平均粒径为130 μm，耐热温度达364℃；E-51-UF@2-MI复合微胶囊质量分数为10wt%时，E-51-UF@2-MI微胶囊/E-51复合材料拉伸强度达到最大值，为31.17 MPa，弯曲强度为66.77 MPa，最大修复率为90.1%。 

Preparation and self-healing properties of epoxy resin-urea formaldehyde resin@2-methylimidazole microcapsules/epoxy resin composites

The epoxy resin-urea-formaldehyde (E-51-UF) microcapsules were synthesized by one-step in-situ polymerization with UF resin as the shell and E-51 as the core material. The structure, surface morphology, heat resistance and particle size distribution of E-51-UF microcapsules were characterized by FTIR, SEM, TG and particle size analyzer. The E-51-UF@2-methylimidazole (2-MI) composite microcapsules were prepared by blending E-51-UF microcapsules as the core and 2-MI as the shell. The E-51-UF@2-MI composite microcapsules were filled in the epoxy resin matrix and E-51-UF@2-MI microcapsules/E-51 composite samples were prepared for the tensile, bending and trapezoidal double cantilever beam (TDCB). The electronic universal testing machine was used to test the properties of the samples. The effects of the mass fraction of E-51-UF@2-MI composite microcapsules on the mechanical properties and self-healing properties of E-51-UF@2-MI microcapsules/E-51 composites were analyzed. The results show that the prepared E-51-UF microcapsules have a regular spherical structure with an average particle size of 130 μm and a heat resistant temperature of 364℃. When the mass fraction of E-51-UF@2-MI microcapsules is 10wt%, the tensile strength of E-51-UF@2-MI composite microcapsules/E-51 composites reaches a maximum of 31.17 MPa, the bending strength is 66.77 MPa and the maximum self-healing ratio is 90.1%.