Moldability and properties of phenolic/artificial zeolite composites

Study on Kneading and Molding of PP/TiO2 Nanocomposite

This paper investigates the kneading and molding of PP (polypropylene) with nano-TiO2 (Titanium dioxide) powder having sizes in the range of 50 nm. It was found that quality feedstock with uniform nanopowder dispersion was achieved only when the kneading was performed for optimum time under optimum torque using a custom-made triple-screw kneader with a high shear stress. The torque and kneading time needed for PP composite with 40 wt.% nano-TiO2 is double that required for the one with 10 wt.%. Rheological and impact properties of composites with 10 wt.% and 40 wt.% filler loading were also analyzed. In addition, a very important result revealed that a simple micro-grating can be successfully used as a mold insert to replicate micro-features made with PP/nano-TiO2 feedstock using injection molding conducted under a high forming pressure and evacuation of the mold.