AbstractAn investigation was made into the effect of coupling agents on the rheological behavior and processability of polypropylene. For the study, each of the following three commercially available coupling agents, a titanate coupling agent (Kenrich Petrochemicals, KR‐TTS) and two silane coupling agents (Union Carbide, A1100 and Y9187), was melt‐blended with polypropylene (PP). Melt blending was performed using a twin‐screw compounding machine. It was found that the zero‐shear viscosity of polypropylene was decreased by 1 order of magnitude after it had been extruded through the twin‐screw compounding machine and that, when coupling agents were added to it, its viscosity was higher than that of the PPwithoutthe coupling agents, undergoing the same deformation history through the twin‐screw compounding machine. Independent measurements of the molecular weight of the materials show that the weight‐average molecular weight (MW) of the extruded PP is 3.77 × 105, whereas theMWof the virgin PP (before extrusion) is 4.80 × 105, indicating that considerable molecular degradation occurred during extrusion and theMWof the PP extrudedwithcoupling agent is greater than that of the PP extrudedwithoutcoupling agent. In other words, the molecular weight measurement supports the viscosity measurements of the PP investigatedwithandwithoutcoupling agent. Also measured were the elongational viscosity of the PPwithandwithoutcoupling agent, which was then correlated to the melt drawability of the materia
展开▼
