Almutairi Mohammed Dukhi, Aria Adrianus Indrat, Thakur Vijay Kumar, Khan Muhammad A
School of Aerospace, Transport and Manufacturing, Cranfield University, Cranfield MK43 0AL, UK.
Biorefining and Advanced Materials Research Centre, Scotland's Rural College (SRUC), Edinburgh EH9 3JG, UK.
Polymers (Basel). 2020 Jul 11;12(7):1534. doi: 10.3390/polym12071534.
Existing self-healing mechanisms are still very far from full-scale implementation, and most published work has only demonstrated damage cure at the laboratory level. Their rheological nature makes the mechanisms for damage cure difficult to implement, as the component or structure is expected to continue performing its function. In most cases, a molecular bond level chemical reaction is required for complete healing with external stimulations such as heating, light and temperature change. Such requirements of external stimulations and reactions make the existing self-healing mechanism almost impossible to implement in 3D printed products, particularly in critical applications. In this paper, a conceptual description of the self-healing phenomenon in polymeric structures is provided. This is followed by how the concept of self-healing is motivated by the observation of nature. Next, the requirements of self-healing in modern polymeric structures and components are described. The existing self-healing mechanisms for 3D printed polymeric structures are also detailed, with a special emphasis on their working principles and advantages of the self-healing mechanism. A critical discussion on the challenges and limitations in the existing working principles is provided at the end. A novel self-healing idea is also proposed. Its ability to address current challenges is assessed in the conclusions.
现有的自修复机制距离全面应用仍有很大差距，大多数已发表的研究仅在实验室层面展示了损伤修复情况。其流变学特性使得损伤修复机制难以实施，因为部件或结构需要持续发挥其功能。在大多数情况下，需要分子键级别的化学反应，并借助加热、光照和温度变化等外部刺激才能实现完全修复。这种对外部刺激和反应的要求使得现有的自修复机制几乎无法应用于3D打印产品，尤其是在关键应用中。本文提供了聚合物结构中自修复现象的概念性描述。接下来阐述了自修复概念是如何受到对自然现象观察的启发。随后描述了现代聚合物结构和部件对自修复的要求。还详细介绍了3D打印聚合物结构现有的自修复机制，特别强调了它们的工作原理和自修复机制的优点。最后对现有工作原理中的挑战和局限性进行了批判性讨论。还提出了一种新颖的自修复理念。在结论部分评估了其应对当前挑战的能力。
