Effect of Carbon Black Loading of Various types on Rheological behavior and Electrical Conductivity of Low Density Polyethylene

Low density polyethylene (LDPE) with various types and concentrations of carbon blacks (CBs) were processed in a Brabender internal mixer at 160°C for 15 min in a closed chamber. A rapid increase in electrical conductivity of all the samples started at a concentration which depends on the type of the CBs. An attempt was focused on the rheological behavior of PE/CBs blends using a capillary rheometer. The rheological data exhibited shear stress, shear viscosities and relaxation modulus changes versus shear rate at different concentrations of various kinds of CBs. The shear stress and viscosities reduced with decreasing contents of CBs at the same shear rate. XE2-B provided the highest shear stress and viscosity compared to the other CBs (L6, V, N330) which was due to its higher structure and surface area. By decreasing the contents of CBs the linear region (i.e. Newtonian) increased. Moreover, power law relationship of flow behavior of the prepared samples compared to the polymer matrix was investigated at different conditions. The presence of CB in the blends lowered the power law exponent (n). XE2-B showed more effective on power law index compared with the other CBs.