Abstract
<jats:p>Plastics are deeply embedded in modern society, yet their production, use, and disposal create significant environmental, economic, and social sustainability challenges. This thesis explores how a transition towards sustainable plastics can be understood from a systems perspective. Combining qualitative and quantitative approaches, the research investigates how technological innovations, governance measures, and resource use interact across the plastics life cycle, and how these interactions relate to wider societal transitions, including those in the energy and industrial sectors. The findings show that effective action requires considering the entire life cycle of plastics and the broader system in which they are embedded, recognising that interventions must be tailored to different contexts. They also highlight that continued growth in plastic production intensifies sustainability challenges, indicating that no technological or policy intervention alone can fully address these challenges without stabilising and ultimately reducing plastics production. By integrating insights from multiple disciplines and methods, this thesis provides a comprehensive framework for understanding plastics sustainability and supporting pathways towards a more sustainable plastics system.</jats:p>