Rheological and mechanical properties of carbon nanotube/Graphite/SS316L/polypropylene nanocomposite for a conductive polymer composite

Highly filled conductive fillers (>60 vol%) for conductive polymer composites (CPCs) cause the degradation of rheological and mechanical properties. This study investigated the rheological properties of highly filled metal powder (SS316L) in a polymer matrix composite combined with carbon nanotubes (CNTs) and Graphite (G). The effects of filler concentrations and chemical functionalization on the mechanical and electrical properties of the resulting CPC were determined. Feedstocks with different concentrations were injection molded, and the molded specimens were subjected to tests of tensile strength, three-point bending, hardness, and three-point probe electrical conductivity. The feedstock of CNTs/G/SS316L can be injection molded from 28 vol% polypropylene (PP). The functionalized CPC shows higher strength and elongation than as-produced CPC based on the tensile and flexural tests. The highest flexural and tensile strengths are 80 and 35 MPa, respectively. The functionalized CPC also exhibits higher hardness and better electrical properties than as-produced CPC. Thus, functionalization with CNTs and Graphite enable the reinforcement and formation electrical conducting networks between metal- and carbon-based fillers within a polymer matrix.