OPTIMIZATION OF CARBON NANOTUBE REINFORCEMENT FOR ENHANCED MECHANICAL PERFORMANCE OF POLYMER NANOCOMPOSITES

Abstract

Carbon nanotube CNT reinforcement strategy to advanced polymer based material applications is a fascinating approach of filling and strengthening in order to improve mechanical, thermal, electrical and other properties of nanocomposite. This paper aims at setting up a solid understanding of the impact that dispersion of CNT, functionalization of CNT and concentration of load in polymer composite has on its mechanical properties. It was also found that lengthened CNT has better dispersion and better mechanical properties, both tensile strength and Young’s modulus, and fracture toughness were enhanced with an optimum value at 3 wt% CNT. From the results it can be concluded that properly dispersed CNTs improved the load transfer efficiency and on the contrary; higher content of CNTs may cause the formation of agglomerated clusters which restrict stress distribution and mechanical properties. Electrical conductivity data show that there is the percolation concentration of CNT being at 3 wt%, which leads to the transition from insulating material to conductive one. Also, the thermal conductivity increases as the CNT contents increase, but there is a limit of improvement since phonon scattering at high CNT content begins to hinder the improvement. SEM and TEM evidence for CNT dispersion to 3 wt% reveal the good agreement with the relationship between high CNT homogeneity and improvements in material properties. This work emphasizes the importance of surface-modification of CNTs, dispersion methods, and processing techniques for improving the properties of nanocomposites. The results are of importance for aerospace, automobile, and electronic industries because such invention demands lightweight, strong, and thermally conductive materials. Further studies should be devoted to the investigation of the combined use of CNTs and other types of reinforcements and to the development of efficient large-scale processing technologies for controlled CNT dispersion and alignment, which would lead to steady mechanical reinforcement in practical applications.