Fabrication and Characterization of Aluminum Oxide-Based Polypropylene Filaments

Polypropylene (PP) is a widely used engineering plastic material that has lightweight and excellent stiffness, but low load-carrying capacity. In order to enhance the load-carrying capacity of pure PP, different types of metallic and non-metallic particles can be added as reinforcement. In fact, mixing and uniform distribution of reinforcing particles in a matrix polymer is a major challenge. Therefore, effective control of fillers and matrix polymer mixing is essential to obtain a better PP composite. In present work, the PP granules are cryogenically grounded into PP powder and mixed with 4, 8, and 12 wt.% of alumina (Al2O3) micro-particles using ball milling process. The single-screw extruder was used to manufacture PP composite filaments of cylindrical cross-section. To examine the distribution of Al2O3 particles on PP, the SEM analysis was conducted which shows that 8 wt.% of Al2O3 got uniformly mixed with PP powders. In addition, tensile test results confirmed that filament having 8 wt.% of Al2O3 holds 34.3% improvement in ultimate tensile strength and 5.8% improvement in break strain.