单组分光敏微胶囊/纳米SiO_(2)/环氧树脂复合绝缘介质的自修复特性

Self-Healing Property of One-Component Photosensitive Microcapsule/Nano-SiO_(2)/Epoxy Composite Dielectric

以环氧树脂为代表的固体绝缘介质在长期电/机械应力作用下不可避免地会产生局部裂纹,严重影响其服役寿命。该文针对上述问题制备一种含有单组分紫外光敏微胶囊的环氧树脂复合绝缘介质,当环氧树脂表面产生裂纹损伤时,机械应力集中于胶囊壳体并使其破裂,囊芯光敏修复剂流出填充损伤通道,在外施紫外激励下实现损伤通道的固化自愈。同时通过向环氧基体内引入纳米SiO_(2)作为紫外光屏蔽介质,实现对囊芯光敏修复剂的紫外保护。该文利用光学显微镜(OM)、扫描电子显微镜(SEM)、傅里叶红外光谱仪、热重分析仪、宽频介电谱分析仪等测试微胶囊与复合介质的本征性能与自修复特性,结果表明,微胶囊壳体致密且均匀,具有良好的耐热性能;SiO_(2)复合介质紫外屏蔽效果显著,能保证囊芯修复剂的反应活性;复合介质在保持环氧材料良好本征性能的同时实现了对机械损伤的自修复。

The solid insulating materials represented by epoxy resin inevitably generate local cracks under long-term electrical/mechanical stress,which seriously affects their service life.In this paper,a novel epoxy insulating composite with one-component UV-photosensitive microcapsules is proposed.When the crack is generated and the microcapsule is broken,the damage channel is filled with the photosensitive healing agent and cured by UV excitation.Meanwhile,nano-SiO_(2) is introduced into the epoxy matrix as an ultraviolet reflecting agent to protect the healing agent in the microcapsule from the premature polymerization.Properties of microcapsules and composites are tested by optical microscope(OM),scanning electron microscope(SEM),infrared spectrometer,thermogravimetric analyzer and dielectric spectrum analyzer.The results show that the microcapsules are compact and uniform,and have good heat resistance.In addition,the SiO_(2) composite matrix has significant UV-shielding effect,which ensures the reactivity of the healing agent from the capsule core.And the composite has an excellent effect on the healing of micro-crack damage while maintaining good intrinsic properties of epoxy resin.