Multiscale Experimental and Numerical Design of a Self-Healing Epoxy Adhesive

自修复环氧粘合剂的多尺度实验和数值设计

• 批准号: 0527965
• 负责人: Philippe Geubelle
• 金额: $ 31万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0527965&HistoricalAwards=false
• 关键词: Multiscale; Experimental; Numerical; Design; Self

Used in many applications ranging from microelectronics to aerospace structures, polymer-based adhesives are often considered as the weak link of bonded structures, including those subjected to cyclic loading. In this collaborative experimental and analytical effort, researchers from the University of Illinois at Urbana-Champaign are designing and demonstrating a new class of heterogeneous, multifunctional, epoxy-based adhesives that possess the unique ability to heal autonomically (i.e., without any external intervention) under fatigue loading, thereby substantially expanding the expected lifetime of adhesive joints. This new class of materials is inspired by living systems, in which damage (e.g., a cut or bruise) triggers an autonomic healing response. In biological systems, chemical signals released at the site of injury initiate a systemic response that transports repair agents to the site of damage and promotes healing. To achieve self-healing capability in the adhesive system studied in this project, sub-micron-size "nanocapsules" containing a monomer healing agent are embedded in the epoxy adhesive layer, together with a living catalyst dispersed in the epoxy matrix. As fatigue-induced microcracks appear and propagate in the adhesive layer, the nanocapsules rupture and release the healing agent. The monomer then mixes with the catalyst phase initiating polymerization and rebonding the crack faces. The research project focuses on (i) materials development with processing and characterization of nanocapsules and identification of viable self-healing chemistries for epoxy adhesives, and (ii) a multi-level numerical and experimental investigation of the fatigue response of a self-healing adhesive joint. The successful completion of this project will lead to the development of a radically new type of adhesive system that present a much enhanced resistance to fatigue failure. Initial observations obtained on "bulk" self-healing composites indicate a five- to ten-fold increase in the fatigue life of epoxy-based components. Furthermore, by integrating multi-level experimental techniques with a new multiscale cohesive finite element framework, this project is expected to yield an integrated design tool for multifunctional adhesive joints with application well beyond the proposed self-healing epoxy-based adhesive system. This research project takes place at the Autonomic Materials Laboratories as part of an interdisciplinary research group at the Beckman Institute for Advanced Science and Technology that involves students and faculty from Aerospace Engineering, Engineering Mechanics, Chemistry and Materials Science.

在从微电子到航空航天结构的许多应用中，聚合物基粘合剂通常被认为是粘合结构的薄弱环节，包括那些承受循环载荷的结构。在这项合作实验和分析工作中，来自伊利诺伊大学厄巴纳-香槟分校的研究人员正在设计和展示一类新的异质，多功能，环氧基粘合剂，具有独特的愈合能力（即，没有任何外部干预），从而大大延长了粘合接头的预期寿命。这类新材料的灵感来自生命系统，其中损害（例如，割伤或擦伤）触发自主愈合反应。在生物系统中，在损伤部位释放的化学信号启动全身反应，将修复剂运送到损伤部位并促进愈合。为了实现自愈合能力在本项目中研究的粘合剂系统中，亚微米尺寸的“纳米胶囊”包含单体愈合剂嵌入在环氧树脂粘合剂层中，连同分散在环氧树脂基体中的活性催化剂。随着疲劳诱导的微裂纹在粘合剂层中出现并传播，纳米胶囊破裂并释放愈合剂。然后，单体与催化剂相混合，引发聚合并重新粘合裂纹面。该研究项目的重点是（i）材料开发与纳米胶囊的加工和表征，以及环氧树脂粘合剂可行的自修复化学的识别，以及（ii）自修复粘合剂接头疲劳响应的多层次数值和实验研究。 该项目的成功完成将导致开发一种全新类型的粘合剂系统，该系统具有更强的抗疲劳破坏能力。对“散装”自修复复合材料的初步观察表明，环氧基组件的疲劳寿命增加了五到十倍。此外，通过将多层次实验技术与新的多尺度内聚有限元框架相结合，该项目预计将产生一个多功能胶接接头的集成设计工具，其应用远远超出了所提出的自愈合环氧基粘合剂系统。该研究项目在自主材料实验室进行，作为贝克曼高级科学与技术研究所跨学科研究小组的一部分，该研究小组涉及航空航天工程，工程力学，化学和材料科学的学生和教师。