A Comparative Study on the Graphitization Behavior of Waste Plastics using Templating Agent
Research Poster Engineering 2025 Graduate ExhibitionPresentation by Shakshi Sekar
Exhibition Number 172
Abstract
This study investigates the upcycling of single-use plastic waste into high-quality synthetic graphite addressing both the growing plastic pollution crisis and increasing graphite demand for clean energy technologies. We examined the graphitization behavior of common waste plastics (polyethylene (PE), high-density polyethylene (HDPE), and polypropylene (PP)) with and without graphene oxide (GO) as a templating agent. Waste plastics were carbonized at 600°C under autogenic pressure and subsequently graphitized at 2500°C. Our results demonstrate that GO addition increased carbon yield across all precursors. High-Resolution Transmission Electron Microscopy (HRTEM) and Selected Area Electron Diffraction (SAED) analyses revealed pronounced differences in nanostructure development, with PP+GO exhibiting superior graphitic quality followed by HDPE+GO. XRD analysis revealed that PE+GO and HDPE+GO composites have crystallite parameters similar to their polymer counterparts, while HRTEM imaging and SAED pattern definition identified significant differences in nanostructure arrangements. This finding emphasizes the importance of employing complementary analytical techniques when evaluating 2D graphitic materials beyond the standard graphitization index.
Importance
In the United States, approximately 16 million tons of single use plastics are used every year which majorly consist of polymers such as HDPE (high- density polyethylene, used in milk jugs), PP (polypropylene, used in yogurt containers and bottle caps) and PE films (polyethylene, used in food packaging and wrapping). Alongside the growing plastic waste crisis, there is an emerging graphite supply shortfall and declining availability of high-quality graphitic carbon precursors. Clean energy technologies, particularly electric vehicles, are driving unprecedented demand for carbon materials. Each electric vehicle requires approximately 70kg of graphite, with just one million EVs (1% of the global market) requiring 75,000 tons of natural graphite. Upcycling plastic waste into graphite simultaneously addresses resource scarcity, meets growing market demand, and reduces environmental impact through circular economy while lowering carbon emissions.