Rheological impact of nano-size fillers in Polycarbonate

Carbon nanotubes (CNTs) are a promising filler material for polymers to change the electrical properties and enhance the mechanical behaviour. These particles are known to increase the melt viscosity of thermoplastics significantly. For the moulding process high melt viscosities are causing various complications. In this study the influence of CNTs and Carbon Black (CB) on the rheological behaviour of a polycarbonate (PC) matrix will be evaluated. CB is a common filler used for antistatic and conductive polymers. In comparison to CNTs, much higher amounts of CB have to be used to create a conductive network. However, CB does not increase the melt viscosity as greatly as CNTs. As it is known, the shape of CB is nearly spherical while CNTs have a fiber shape. It is expected that combining these two different geometries will result in a lower inner friction therefore their composites will show a lower viscosity. Aim of this study is to investigate, if a hybrid composite is able to achieve the same electrical conductivity like a CNT composite but with a lower melt viscosity