(354a) Graphitic Carbons By Upcycling Consumer Plastic Waste By Graphene Oxide Additives: Mechanism(s) and Characterization

In the United States, approximately 37 million tons of plastic are used every year according to the McKinsey estimates. Packing and food-service uses contribute 16 million tons which is single use disposable plastic. More than 70% of the single use plastic waste is sent to landfills. This presents a huge opportunity to upcycle the plastic waste into high value carbon materials. Concurrently a big surge in demand for carbon materials is expected from energy storage and transportation applications. Present electric vehicles require ~70 kg graphite. An EV adoption of 1% of the new car market will potentially increase graphite demand by 10%.

When heated, plastics typically crack into light gases through chain unzipping and β-bond scission. This translates into low carbon yield and non-graphitizable residual carbon. We propose an innovative approach of employing GO as templating agent and closed reactor carbonization under autogenic pressure to increase yield and graphitic quality of carbons. Oxygen functional groups on GO would provide the necessary stabilization while the sp2 framework would serve as a template guiding reconstruction of polymer chains into graphitic material. The latter postulated templating effect could realize significant cost and energy savings by enabling graphitic structure at lower temperatures. Notably, a portion of this graphitic material could be used to derive the GO for templated graphitization of fresh feedstock, thus contributing to circular process and upcycling plastic economics. Upcycling overabundant plastic waste into graphitic carbons will reduce pollution, cost and CO2 emissions. Four commercially recycled plastics and their composites with GO have been used to evaluate comparative yield and graphitic quality of the obtained carbon materials. The key advantage of GO as additive is that it nets a substantial increase in carbon yields, nearly 300% in some plastics. GO/plastic composites possess lattice parameters comparable to graphitized anthracene coke.