Circularity of Plastics: Sustainability, Emerging Materials, and Valorization of Waste Plastic takes an innovative, interdisciplinary approach to circularity and sustainability in plastics, with an emphasis on plastic waste and end-of-life treatment and options for recycling, re-use, valorization and development of biomass-based polymers. The book introduces key concepts of sustainable materials, the circular economy, and lifecycle assessment, and discusses challenges in the valorization of waste. Other sections cover the upcycling of waste plastic into new materials and fuels, with dedicated chapters exploring state-of-the-art techniques for conversion to new sustainable polymers, fuel, fine chemicals and carbon nanomaterials. Emerging technologies used to produce functional polymers from renewable feedstocks, including CO2, biomass, natural polymers, polylactic acid (PLA), and polyhydroxyalkanoate-based materials (PHAs) are then explored, with a final chapter focusing on applications of sustainable materials, challenges, and future perspectives. This is a valuable resource for researchers, scientists, engineers, R&D professionals, and advanced students from a range of disciplines and backgrounds, with an interest in sustainable materials, circularity in plastics, and polymer waste and valorization.