CHARACTERIZATION OF CONTINUOUS CARBON NANOTUBE YARNS

Abstract

An approach on tensile testing is established for the mechanical characterization of two types of continuous carbon nanotube (CNT) yarns for potential aerospace-grade composite laminate applications. CNT yarns with around 80% alignment achieved a specific tensile strength of 1.66 N/tex and a specific tensile modulus of 84.64 N/tex. We studied the effects of resin cure cycles, moisture levels, and cyclical loading on the yarn’s mechanical properties. The results show that the specific strength and specific modulus of CNT yarns were unaffected by the temperature parameters of the BMI resin cure cycle. Hysteresis tests were performed to examine the resistance of CNT yarns to loading cycles, resulting in slight strain hardening and a 4-6 % increase in the specific strength and modulus of yarns. CNT yarns were moisture conditioned in wet, dry, and ambient environments to determine the effect of moisture content on mechanical performance. Yarn properties increased by up to 10% when ambient moisture was removed from the system. The results provide valuable insights to understand tensile properties and behaviors of high strength continuous CNT yarns with multiscale microstructures.