Effect of fillers developed with rare earth elements and carbon fibre powder on mechanical, thermal and morphological properties of polypropylene

In this study, the effects of fillers prepared with carbon fiber powder and the rare earth elements lanthanum oxide and cerium oxide on the mechanical, thermal, and morphological properties of polypropylene, a thermoplastic polymer, were investigated. Lanthanum oxide and cerium oxide were separately dissolved in water, and carbon fiber powder was added to these solutions. The solutions were stirred on a magnetic stirrer at 90 to 100°C until the water in the solutions evaporated. This mixture was then added to a low-density polyethylene solution, forming a new composition.After drying, the prepared filler materials were ground into particles using a milling machine. The ground particles were then mixed with polypropylene at weight ratios of 10%, 20%, and 30%, and a melt flow analysis was performed. Subsequently, the PP and the produced filler materials were mechanically mixed at weight ratios of 10%, 20%, and 30% and then homogeneously blended in an extruder. The extruded strip material was cooled by passing through water and then crushed into granules of 2 to 3 mm in size. The obtained granules were molded into standard test specimens using an injection molding machine.Tensile, bending, and Charpy impact tests were conducted on the produced composite test specimens. Additionally, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analyses were performed to examine the changes in the thermal properties of the composite materials. Furthermore, scanning electron microscopy was used to investigate the bonding mechanisms between the filler material and the matrix material.Tensile test results showed that increasing the filler content led to a decrease in the tensile strength of the composite materials. While the tensile strength of pure PP samples was found to be an average of 31.23 MPa, the tensile strength of NM7 samples, which contained 10% carbon fiber powder reinforced with cerium, was determined to be 32.05 MPa. It was found that the NM7 composite material was the only material with higher tensile and three-point bending strength compared to pure PP.