COMPARATIVE STUDY OF THE PHYSICO-MECHANICAL PROPERTIES OF COMPOSITES WITH CARBON NANOFIBRES (CNF) AND MULTIWALL CARBON NANOTUBE (MWCNT) IN A POLYETHER SULFONE (PES) MATRIX

Abstract

In this research new composite materials have been developed  by combining carbon nanotubes (MWCNT), carbon nanofibers(CNF) and polyether sulfone  (PES).The mixtures were prepared by melting them together in an extruder and then the injection was molded with lots of MWCNT (1, 3 and 5% by weight) and CNF (2.5, 5 and 10% by weight). Differential scanning calorimetry (DSC) was used to study the thermal transitions of the matrix. The viscoelastic properties were measured through a dynamic-mechanical analyzer (DMA), with an increase of elastic modulus (G') and with the addition of carbon nanoparticles. The evaluation of mechanical properties among all the compounds tested showed greater efficiency in those containing MWCNT. Using the linear elastic fracture mechanics (LEFM), tests were conducted on the impact of Charpy in order to determine the value of Gc by Plati and Williams method. The dispersion of the MWCNT and CNF were analyzed on the fracture surface obtained from tensile tests by SEM. Although the fibers were not pre-treated the micrographs revealed a better distribution of carbon nanotubes in the matrix.