A transesterification-based epoxy vitrimer synthesis enabled high crack self-healing efficiency to fibrous composites

• Published in: Composites. Part A, Applied science and manufacturing Vol. 162; p. 107170
• Main Authors: Wu, Pan, Liu, Ling, Wu, Zhanjun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2022
• Subjects: A.Laminate; A.Multifunctional composites; adipic acid; B. Delamination; B. Self-healing; carbon nanotubes; crosslinking; epoxides; liquid nitrogen; temperature; tensile strength; A.Laminate; B. Self-healing; B. Delamination; A.Multifunctional composites
• ISSN: 1359-835X; 1878-5840
• DOI: 10.1016/j.compositesa.2022.107170

[Display omitted] •A dicarboxylic acid, a general epoxy resin and a primary amine (and CNTs) are used to synthetize a novel epoxy vitrimer with improved transesterification rate.•The epoxy vitrimer has good self-healing efficiency to their own cracks as well as to the delamination crack of CFRP with epoxy vitrimer matrix.•The obtained CFRP show effective self-healing ability to manufacturing defects and low-temperature induced microcracks. Adipic acid was grafted onto a general epoxy resin and then crosslinked with a primary amine to synthesize a novel remenable epoxy vitrimer (EPV). Also, carbon nanotubes were added into EPV to obtain reinforced EPVC. Results reveal that EPV and EPVC show good self-healing efficiencies to their respective cracks, i.e. 74–77 % to fracture toughness and 62–67 % to tensile strength. But EPVC shows higher toughness and strength, respectively increased by 80 % and 3.2 % when compared with EPV. Also, the obtained fibrous composites are resistant to low temperature and the increased crack density is only 0.02 % after soaking in liquid nitrogen for 20 days, which can be completely healed by thermal activation. Moreover, EPV and EPVC-based laminates show a self-healing efficiency greater than 100 % to interlaminar toughness and strength after two loading-healing cycles. The EPVC laminate also has higher initial mechanical properties. Thus, the synthesized EPV/EPVC is potential in preparing self-healing structural composites.