Dynamic behavior of carbon nanofiber-modified epoxy with the effect of polydopamine-coated interface

Abstract

Understanding the dynamic mechanical behaviors of nano-modified composites are essential for designing the anti-collision structures. In this work, carbon nanofibers (CNFs) were coated by mussel-inspired polydopamine ad-layer for modifying the interface and dispersion behaviors while incorporated into epoxy. Quasi-static and dynamic compression mechanical responses of CNFs-modified epoxy were systematically investigated. The polydopamine-coated CNFs composites (D-CNFs/epoxy) show the improved strength and strain energy density in comparison with the pristine CNFs/epoxy. The results also indicate that the yield stress and stress-softening properties of polydopamine-coated-CNFs/epoxy are more sensitive to strain rate compared with the neat epoxy and pristine CNFs/epoxy. An empirical constitutive equation in consideration of the strain rate and the strain-softening was proposed to characterize the stress–strain curve. The equivalent epoxy/filler simulation model was built to reveal that a higher interface friction is beneficial in improving the strength of composites, but deteriorating the strength while the interface friction is lower than a certain value.

Keywords:

• Bio-inspired coating
• dynamic behavior
• interface
• strain rate
• strain-softening

Disclosure Statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (Grant Nos. 11602267, 11872361, 11672286, and 11472264). The project supported by Anhui Provincial Natural Science Foundation (Grant No. 1708085MA05). This work was also supported by the Fundamental Research Funds for the Central Universities (WK 2090050040, WK 2480000003).