Abstract Although widely used in aviation and aerospace engineering over the last several decades, textile-reinforced epoxy composites always suffer from their relatively poor out-of-plane properties, due to the inherent brittleness of epoxy matrix. In this work, a concept of interlaminar toughening tackifier is proposed to simultaneously enhance the interlaminar properties and process efficiency during manufacture of textile-reinforced epoxy composites via liquid composites molding (LCM) processes. A new interlaminar toughening tackifier polyamide 6/graphene oxide (PA6/GO-1.0) was prepared successfully via in situ polymerization and ethanolic solution precipitation methods. Through sufficient evaluation by standard double cantilever beam (DCB) tests and end notched flexure (ENF) tests, interlaminar fracture toughness of textile-reinforced epoxy composites exhibited an effective enhancement of 80.6% and 36.2% under mode I and mode II deformation, respectively. The mechanism for the excellent interlaminar properties are discussed thoroughly based on careful fractographic study of the delaminated composites. T-peel tests were also performed to assess the interply adhesion properties of PA6/GO-1.0. Moreover, for the best interlaminar fracture toughness, the dosage of GO is no more than 0.05 wt% to the textile reinforcements, providing an economically feasible method to balance the mechanical properties and process efficiency.

中文翻译：

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使用聚酰胺 6/氧化石墨烯层间增韧增韧剂增强织物增强环氧树脂复合材料的层间断裂韧性

摘要 尽管在过去几十年中广泛应用于航空航天工程，但由于环氧树脂基体固有的脆性，纺织增强环氧树脂复合材料始终存在其相对较差的面外性能。在这项工作中，提出了层间增韧增粘剂的概念，以在通过液体复合材料成型 (LCM) 工艺制造纺织增强环氧树脂复合材料期间同时提高层间性能和工艺效率。通过原位聚合和乙醇溶液沉淀方法成功制备了一种新型层间增韧增粘剂聚酰胺6/氧化石墨烯（PA6/GO-1.0）。通过标准双悬臂梁 (DCB) 测试和端部缺口弯曲 (ENF) 测试的充分评估，织物增强环氧树脂复合材料的层间断裂韧性在模式 I 和模式 II 变形下分别表现出 80.6% 和 36.2% 的有效增强。基于对分层复合材料的仔细断口研究，深入讨论了优异层间性能的机制。还进行了 T 剥离测试以评估 PA6/GO-1.0 的层间粘合性能。此外，为了获得最佳的层间断裂韧性，GO 对织物增强材料的用量不超过 0.05 wt%，为平衡机械性能和工艺效率提供了一种经济可行的方法。基于对分层复合材料的仔细断口研究，深入讨论了优异层间性能的机制。还进行了 T 剥离测试以评估 PA6/GO-1.0 的层间粘合性能。此外，为了获得最佳的层间断裂韧性，GO 在织物增强材料中的用量不超过 0.05 wt%，为平衡机械性能和工艺效率提供了一种经济可行的方法。基于对分层复合材料的仔细断口研究，深入讨论了优异层间性能的机制。还进行了 T 剥离测试以评估 PA6/GO-1.0 的层间粘合性能。此外，为了获得最佳的层间断裂韧性，GO 在织物增强材料中的用量不超过 0.05 wt%，为平衡机械性能和工艺效率提供了一种经济可行的方法。