A Study on Mechanical Properties of MWNT/PMMA nanocomposites

Abstract

Multi-walled carbon nanotube (MWNT) /poly (methyl methalcrylate) composites were fabricated with the variation of the nanotube-concentraion through film casting. It was confirmed that the nanotubes were well dispersed in PMMA according to SEM images. To investigate the mechanical properties of the MWNT/PMMA nanocomposites, tensile tests were performed varying the MWNT-concentrations. As the MWNT concentration increased from 0 to 0.15 wt%, MWNT/PMMA nanocomposites were improved by about 20% in the tensile strength and by about 32% in the tensile modulus. Because MWNTs in MWNT/PMMA nanocomposites were assumed to be randomly oriented, the tensile modulus of the nanocomposite was evaluated through the Tsai-Pagano equation which has been applied to short fiber composites for estimating their modulus. However, the estimateed results were not in agreement with the experimental results from tensile tests. It is attributed to two reasons. First, MWNTs in this research were not stretched straightly but entangled ones. That is, MWNT could not be assumed to be a short fiber. Second, the concentration of MWNT is too small to be compared with that of the short fiber composites.