Modeling of Tensile Modulus and Strength of Carbon Nanotube Reinforced Polymer Nancomposites

Abstract

Carbon nanotubes (CNTs) possessing extremely high stiffness, strength, and resilience would be the ultimate reinforcing materials for the development of polymer reinforced nanocomposites. CNTs are promising new materials for blending with polyme rs with potential to obtain low -weight nanocomposites of extraordinary mechanical, electrical, thermal and multifunctional properties. Unlike conventional fiber reinforced composites, there are wide variations in the diameter and length of the CNTs in the CNTs reinforced composites. In this work a numerical model has been developed to calculate tensile modulus and tensile strength of randomly oriented short CNTs reinforced composites considering the statistical variation of diameter and length of the CNTs . According to this model, the whole composite is divided into several composite segments which contain CNTs of almost same diameter and same length. Tensile modulus and tensile strength of the composite is then calculated by weighted summation of the corr esponding modulus and strength of each composite segment. Existing micromechanical approach for modeling of short fiber reinforced composites is modified to account for the structure of the CNTs to calculate the modulus and strength of each segmented CNTs reinforced composites. To consider the CNTs structure, multi -walled CNTs with and without intertube bridging have been considered. Statistical variations of the diameter and length of the CNTs are modeled by the normal distribution. Effects of intertube bridging in multi-walled CNTs and variations of CNT diameter and length on the tensile modulus as well as tensile strength of the CNTs reinforced nanocomposites have been investigated using this developed model. Results obtained from this numerical model h ave also been compared with the available experimental results and the comparison concludes that the developed model can be used to predict tensile modulus and tensile strength of CNTs reinforced nanocomposites.