Self-healing behavior of polyurethanes based on dual actions of thermo-reversible Diels-Alder reaction and thermal movement of molecular chains
Self-healing behavior of polyurethanes based on dual actions of thermo-reversible Diels-Alder reaction and thermal movement of molecular chains
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基于热可逆Diels-Alder反应和分子链热运动双重作用的聚氨酯自修复行为
DOI：
10.1016/j.polymer.2017.07.049
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发表时间：
2017-08-25
期刊：
影响因子：
4.6
通讯作者：
Chai, Changsheng
中科院分区：
文献类型：
--
作者：
Feng, Libang;Yu, Zhengyang;Chai, Changsheng
材料中产生的裂纹影响材料的综合性能，缩短材料的使用寿命。这一问题有望通过赋予材料自修复特性来解决。本文研制了一种具有优良自修复性能的热塑性聚氨酯（PU-DA），并对其自修复行为进行了定性观察和定量测定。结果表明，由于引入了Diels-Alder（DA）键，PU-DA具有优异的热可逆性，热可逆DA反应和分子链热运动的双重作用可以修复聚氨酯膜中的裂纹。DA键及其热可逆性对力学性能的恢复起着重要作用，分子链的热运动效应起着辅助恢复力的作用，加速了整个愈合过程。不同软段和不同-NCO/-OH值的PU-DA的自修复行为进一步证实了优异的自修复性能确实是基于联合作用。此外，自修复聚氨酯具有出色的再加工性能，使废旧聚氨酯的回收利用成为可能。这项研究使一般点DA热可逆性已经知道，以及自我修复能力和热可逆性之间的联系，随着热运动沿着的演示重新演示。(C)2017爱思唯尔有限公司版权所有
Cracks generated in materials affect comprehensive performance and shorten service life of materials. The problem is expected to be resolved by endowing materials with self-healing property. Herein, a new thermoplastic polyurethane with excellent self-healing performance (PU-DA) has been developed, while the self-healing behavior is investigated by qualitative observation and quantitative measuring comparatively. Results reveal that PU-DA exhibits excellent thermal reversibility due to incorporated Diels-Alder (DA) bonds, and cracks in polyurethane films can be repaired by dual actions of thermo-reversible DA reaction and thermal movement of molecular chains. DA bond and its thermal reversibility contribute much to the recovery of the mechanical property while the thermal movement effect of molecular chains acts as an auxiliary recovering force which accelerates the whole healing process. The self-healing behavior of PU-DAs from diverse soft segments and different -NCO/-OH values further confirms that the excellent self-healing performance is grounded on combined actions indeed. Additionally, the self-healing polyurethane presents outstanding reprocessing performance, and which makes it possible of recycling waste polyurethanes. This study enables the re-demonstration of general points about DA thermal reversibility already known, as well as presentation of link between self-healing capability and thermal reversibility along with thermal movement. (C) 2017 Elsevier Ltd. All rights reserved.