Melt Rheological and Impact Properties of Thermally Stable PP/mLLDPE Blends

Effect of the heat stabilizer on the melt rheological properties of the blends of polypropylene (PP) with mLLDPE (mettalocene linear low density polyethylene), after thermal degradation in an air oven, was studied. Study carried out is presented to describe the effect of blending ratio and presence of stabilizer on shear stress, shear rate, melt viscosity and melt elasticity parameters. In general, blending of PP with mLLDPE results in an increased viscosity. The viscosity of PP abruptly decreases after the thermal degradation. Interestingly the melt viscosity PP/mLLDPE blend does not show such a marked decrease. This shows that mLLDPE not only acts as an impact modifier but also acts as a thermal stabilizer. The presence of stabilizer in both materials has not shown much difference in melt viscosity thereby suggesting adequate stabilization of the blend system.