Room-Temperature Self-Healing Polymers Based on Dynamic-Covalent Boronic Esters
Room-Temperature Self-Healing Polymers Based on Dynamic-Covalent Boronic Esters
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DOI：
10.1021/acs.macromol.5b00210
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发表时间：
2015-04-14
期刊：
影响因子：
5.5
通讯作者：
Sumerlin, Brent S.
中科院分区：
文献类型：
--
作者：
Cash, Jessica J.;Kubo, Tomohiro;Sumerlin, Brent S.
采用光引发自由基硫醇-烯点击化学方法合成了动态共价型硼酸酯交联聚合物。由于硼酸酯交联的可逆性很容易获得，因此所得到的材料能够在失效后进行键交换以共价修复。在室温下，硼酸酯在水中的可逆键改变了它们的交换平衡。然而，观察到这些材料是稳定的和疏水性的，当浸入水中或暴露在潮湿环境中时，在较长的时间内只吸收少量的水。网络的灵活可逆性允许在环境条件下进行内在的自我修复。这些块状材料的高效自愈通过机械测试得到证实，即使在对单个部位进行多次切割修复周期后也是如此。考虑了几个变量对材料性能和愈合的影响，包括交联剂密度、湿度和愈合时间。
Cross-linked polymers constructed with dynamic-covalent boronic esters were synthesized via photoinitiated radical thiol-ene click chemistry. Because the reversibility of the boronic ester cross-links was readily accessible, the resulting materials were capable of undergoing bond exchange to covalently mend after failure. The reversible bonds of the boronic esters were shown to shift their exchange equilibrium at room temperature when exposed to water. Nevertheless, the materials were observed to be stable and hydrophobic and absorbed only minor amounts of water over extended periods of time when submerged in water or exposed to humid environments. The facile reversibility of the networks allowed intrinsic self-healing under ambient conditions. Highly efficient self-healing of these bulk materials was confirmed by mechanical testing, even after subjecting a single site to multiple cut-repair cycles. Several variables were considered for their effect on materials properties and healing, including cross-link density, humidity, and healing time.