Effect of carbon nanotubes growth topology on the mechanical behavior of hybrid carbon nanotube/carbon fiber polymer composites

In this study, carbon nanotubes (CNTs) were incorporated into carbon fiber‐reinforced polymer composites (CFRPs) by growing them on the surface of PAN‐based carbon fibers utilizing a relatively low temperature technique. The effect of various surface treatments of the carbon fibers on the in‐plane and out‐of‐plane mechanical performance of the hybrid CFRPs (e.g., exposure to or shielding against elevated temperatures, patterned vs. unpatterned growth of the CNTs over the carbon fibers) were investigated. The in‐plane quasi‐static mechanical properties and out‐of‐plane dynamic properties of the hybrid CFRPs were examined utilizing tension and dynamic impact tests, respectively. To study the progressive damage mechanism of the hybrid CFRPs, spherical punch tests as well as X‐ray radiography of the impact damaged hybrid CFRPs were carried out. The results revealed that the strength and impact energy dissipation of the CFRPs improved by 11% and 127%, respectively, utilizing patterned growth of CNTs on the surface of the carbon fibers. POLYM. COMPOS., 37:2639–2648, 2016. © 2015 Society of Plastics Engineers