Abstract In this work, the effect of common functional groups, namely hydroxyl, formyl, carboxyl, and amine groups on the interfacial behavior of surface-modified glass fiber-reinforced epoxy is investigated at molecular scale. The interfacial properties of the epoxy/silica coated with different functional group systems are quantified by performing pulling test using the steered molecular dynamics simulations. It is found that the system with hydroxyl groups has a relatively lower interfacial interaction, exhibiting an adhesive failure mode. When partial hydroxyl groups are replaced by carboxyl, amine, and formyl groups, respectively, the interfacial interactions are increased and these systems exhibit a cohesive failure mode where failure happens in the epoxy close to interface. A relatively higher force is required for the adhesive debonding, while more energy can be dissipated for the cohesive debonding. Because the increased interfacial interactions can prevent the mobility of polymer chains, and delay the propagation of micropores in the matrix, leading to the epoxy matrix with a high ability of energy absorption. Our work provides an insight into how functional groups affect the interface debonding behavior of glass fiber-reinforced epoxy, offering a guideline for control of the interfacial properties of such composites through surface modification techniques.

中文翻译：

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表面改性对玻璃纤维增​​强环氧树脂界面性能的影响：分子动力学研究

摘要 在这项工作中，在分子尺度上研究了常见官能团，即羟基、甲酰基、羧基和胺基对表面改性玻璃纤维增​​强环氧树脂界面行为的影响。通过使用受控分子动力学模拟进行拉伸测试来量化涂有不同官能团系统的环氧树脂/二氧化硅的界面性质。发现具有羟基的体系具有相对较低的界面相互作用，表现出粘合失效模式。当部分羟基分别被羧基、胺和甲酰基取代时，界面相互作用增加，这些系统表现出内聚失效模式，其中失效发生在靠近界面的环氧树脂中。粘合剂剥离需要相对较高的力，而内聚剥离需要消耗更多的能量。因为增加的界面相互作用可以阻止聚合物链的移动，延缓微孔在基体中的传播，从而使环氧树脂基体具有较高的能量吸收能力。我们的工作深入了解了官能团如何影响玻璃纤维增​​强环氧树脂的界面剥离行为，为通过表面改性技术控制此类复合材料的界面性能提供了指导。导致环氧树脂基体具有高能量吸收能力。我们的工作深入了解了官能团如何影响玻璃纤维增​​强环氧树脂的界面剥离行为，为通过表面改性技术控制此类复合材料的界面性能提供了指导。导致环氧树脂基体具有高能量吸收能力。我们的工作深入了解了官能团如何影响玻璃纤维增​​强环氧树脂的界面剥离行为，为通过表面改性技术控制此类复合材料的界面性能提供了指导。