Bonding performances of epoxy coatings reinforced by carbon nanotubes (CNTs) on mild steel substrate with different surface roughness. (August 2021)

• Record Type: Journal Article
• Authors: Zhang, Dawei; Huang, Ying; Wang, Yechun
• Is Part Of: Composites. Volume 147(2021)
• Publication Date: 2021-08
• Subjects: Carbon nanotubes and nanofibers -- Resins -- Debonding -- Mechanical testing; Composite materials -- Periodicals; Manufacturing processes -- Periodicals; Composite materials; Manufacturing processes; Periodicals; 620.11805
• DOI: 10.1016/j.compositesa.2021.106479
• Languages: English
• ISSNs: 1359-835X

Abstract

Highlights: The addition of CNTs could greatly improve the bonding performance of epoxy coatings. The reinforcing mechanisms of CNTs are improvements in toughness and interfacial adhesion. The bonding performance of CNTs-reinforced epoxy coatings increases with surface roughness. The failure mode could be only changed into partly cohesive failure due to CNTs aggregations. Abstract: This paper investigated the bonding performances of epoxy coatings reinforced by carbon nanotubes (CNTs) as additives on mild steel substrates. Pure epoxy and CNT-reinforced epoxy coatings on four different surface roughness of steel substrate were tested using single lap shear (SLS) tests. The SLS experimental results indicated that, on rougher substrates, the addition of a small percentage of CNTs (0.75% by weight) could significantly improve the bonding performance and change the failure mode from adhesion fracture to partly cohesive failure by improving the toughness of coatings and the interfacial adhesion between the coatings and substrates. In addition, the contact angle tests and the surface characterizations using scanning electron microscopy (SEM) analysis before and after fracture indicated that the wettability of coatings on steel substrates improved significantly with the increase of surface roughness and mechanical interlocking was the main reinforcing mechanism on rougher substrates.