Development of alternative carbon fibre powder and rare earth element‐based filler for high density polyethylene

This study developed alternative fillers to enhance the flowability of high‐density polyethylene (HDPE). Lanthanum and cerium oxide with over 90 % purity were used as binder interfacial elements in fillers developed using both carbon fiber powder wastes and powder coating wastes. Polyethylene gel was used to make the fillers thermoplastic and homogenous. A total of six different fillers were developed and melt flow index analyses were performed. As a result of these analyses, it was found that the fluidity of high‐density polyethylene improved significantly, especially with fillers containing carbon fiber powder. As a result, high‐density polyethylene mixtures containing 10 %, 20 %, 30 %, 40 %, and 50% by weight of carbon fiber powder‐based fillers were pressed into molds by a plastic injection molding machine, and samples were produced. According to the mechanical analysis results of these specimens, tensile and flexural strengths decreased slightly depending on the filling ratio, while the impact strengths remained constant. Differential scanning calorimetry analysis was performed to determine the glass transition temperature and melting/crystallization temperatures of the obtained mixtures, while thermogravimetric analysis was performed to determine the mass losses. At the same time, electron microscope analysis of the cross sections of the samples were performed.