Reversing fatigue in carbon-fiber reinforced vitrimer composites
Reversing fatigue in carbon-fiber reinforced vitrimer composites
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DOI：
10.1016/j.carbon.2021.10.078
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发表时间：
2021-11-08
期刊：
影响因子：
10.9
通讯作者：
Koratkar, Nikhil
中科院分区：
文献类型：
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作者：
Kamble, Mithil;Vashisth, Aniruddh;Koratkar, Nikhil
尽管经过了几十年的研究，疲劳仍然是碳纤维增强聚合物(CFRP)复合材料灾难性破坏的罪魁祸首。现有的抗疲劳方法通常是基于纳米级的添加剂，这种添加剂可以减缓聚合物中裂纹的增长。虽然这延长了疲劳寿命，但它不能避免最终的失效，因为裂纹的增长正在放缓，而不是逆转。其他方法已经探索了自我修复聚合物，释放一种固化剂来修复局部损伤。然而，这种方法也不能解决疲劳问题，因为一旦固化剂释放出来，它就会被消耗掉，不能再使用。为了解决疲劳的不可逆性，我们在这里报告了一种硫酸体系，对于该体系，通过将材料加热到其拓扑冻结转变温度以上，可以反复实现疲劳损伤的逆转。这使得疲劳引起的损伤能够间歇性愈合，因为它积累在玻璃体基质中。利用这种方法，我们证明了玻璃体和碳纤维增强玻璃体(VCFRP)中的疲劳破坏可以无限期地推迟。这种vCFRP可以为未来的材料打开大门，其中自然老化和疲劳过程可以周期性地逆转，从而保证安全可靠的长期运行。
Despite decades of research, fatigue remains the primary culprit for catastrophic failure in carbon-fiber reinforced polymeric (CFRP) composites. Existing approaches to combat fatigue are usually based on nano-scale additives that slow the growth of cracks in the polymer. While this prolongs fatigue-life, it cannot avert eventual failure since crack growth is being slowed and not reversed. Other approaches have explored self-healing polymers that release a curing agent to repair local damage. However, this approach also fails to tackle fatigue, since once the curing agent is released, it gets consumed and cannot be re-used. To addresses the irreversibility of fatigue, we report here a vitrimeric system, for which reversal of fatigue damage can be achieved repeatedly, by heating the material to above its topology freezing transition temperature. This enables intermittent healing of fatigue-induced damage, as it accumulates in the vitrimer matrix. Using this approach, we show that fatigue failure in vitrimers and in carbon-fiber reinforced vitrimers (vCFRP) can be postponed indefinitely. Such vCFRPs could open the door to future materials, in which natural aging and fatigue processes can be periodically reversed, so as to guarantee safe and reliable long-term operation.