Melt Rheology of Thermoplastic Elastomers from High Density Polyethylene/Styrene – Butadiene Rubber Blends: Effect of Blend Ratio and Dynamic Vulcanization

Abstract

The melt rheological behavior of HDPE/Styrene butadiene Rubber blends has been investigated with special reference to the effect of blend ratio, shear stress and temperature using capillary rheometer. HDPE/SBR blends show pseudoplastic behavior, which evidenced by the decrease in viscosity with increase in shear rate. The flow behavior index also support the pseudoplastic nature of these blends. The viscosity of the blends increase as the amount of SBR increases. The shear viscosity versus composition of the blends showed negative deviation, which is more pronounced at low shear rates. Various theoretical models are used to predict the melt viscosity of the blends. The influence of dynamic crosslinking using different curing systems on the rheological properties of the blends has been analyzed. A shear-rate superposition analysis has been done to predict the melt viscosities of the system as a function of temperature. Using a plot of modified shear stress versus shear rates; it is seen that various curves were unified as a single master curve.