Kim Sunyoung, Kim Bo-Hyun, Oh Myongkeon, Park Dong Hyuk, Lee Sunjong
Korea Institute of Industrial Technology, Chenan, Chungnam 31056, Korea.
Department of Applied Organic Materials Engineering, Inha University, Incheon 402-751, Korea.
Polymers (Basel). 2019 Jan 9;11(1):104. doi: 10.3390/polym11010104.
Self-healing, an autonomous repairing process stimulated by damage, has recently attracted a great deal of attention in the field of medical and mechanical engineering as well as from scientists, due to its valuable potential applications. However, as the self-healing process is mediated by specific functional materials, practical applications have been limited. Here, we introduce a healable homopolymer microcapsule that can self-heal a crack or cleaved part through a photochemical [2 + 2] cycloaddition process. Microcapsules were prepared through photopolymerization and suspension polymerization, each containing 1,1,1-tris (cinnamoyloxymethyl) ethane (TCE) and 1,1-di (cinnamoyloxymethyl) ethane (DCE) monomers, which act as healing materials. TCE and DCE monomers were polymerized into poly (TCE-co-DCE) without a photoinitiator under illumination. The epoxy specimen embedded with microcapsules showed obvious healing performance during illumination after cracking. From the FT-IR spectra for each step of the healing process, the specimen could be repeatedly self-healed through the reversible process of cyclobutane cross-links to the original cinnamate and vice versa. This work shows an alternative approach using homopolymer microcapsules to accomplish the repeatable self-healing of a crack without interface discontinuity, which could be adopted as a healing substance in various paints.
自修复是一种由损伤引发的自主修复过程，由于其具有潜在的重要应用价值，近年来在医学、机械工程领域以及科学界都备受关注。然而，由于自修复过程是由特定功能材料介导的，其实际应用受到了限制。在此，我们介绍一种可自愈的均聚物微胶囊，它能够通过光化学[2 + 2]环加成过程自愈裂缝或断裂部分。微胶囊通过光聚合和悬浮聚合制备，每个微胶囊都含有作为修复材料的1,1,1-三（肉桂酰氧基甲基）乙烷（TCE）和1,1-二（肉桂酰氧基甲基）乙烷（DCE）单体。在光照下，TCE和DCE单体在无光引发剂的情况下聚合成聚（TCE-co-DCE）。嵌入微胶囊的环氧树脂试样在开裂后的光照过程中表现出明显的自愈性能。从愈合过程各步骤的傅里叶变换红外光谱来看，试样可以通过环丁烷交联与原始肉桂酸酯之间的可逆过程反复自愈，反之亦然。这项工作展示了一种使用均聚物微胶囊实现裂缝可重复自愈且无界面不连续性的替代方法，该方法可作为各种涂料中的一种修复物质。
