Effects of CNT Diameter on the Uniaxial Stress‐Strain Behavior of CNT/Epoxy Composites

Abstract

The present work studies the effects of the diameter of carbon nanotube (CNT) as well as CNT weight fraction on the uniaxial stress‐strain behavior, stiffness, and strength of CNT‐reinforced epoxy‐matrix composites. The experimental results show that average Young′s moduli of 5 wt%‐CNT/epoxy composites with a CNT diameter D < 20 nm and D = 40 ~ 60 nm are 4.56 GPa and 4.36 GPa, and the average tensile strengths are 52.89 MPa and 46.80 MPa, respectively, which corresponds to a percentage increase of 61.1%, 54.1%, 106%, and 82.3%, respectively. Two micromechanics models are employed and the predicted Young′s moduli are benchmarked with the experimental data of MWCNT‐reinforced epoxy‐matrix composites.