Currently, large amounts of plastic waste are incinerated or landfilled, despite the existence of several recycling routes. In this book, a roadmap is provided to increase the amount of recycled plastic waste. Focus is on poly(methyl methacrylate), PMMA, which is used for optical, electronic, composite and coating applications. The entire recycling chain, from collection of plastic waste, to recycling, purification and repolymerization of regenerated monomers, and end-user applications, is covered. • A unique roadmap is given to increase polymer circularity. • PMMA depolymerization via twin-screw technology, linking the molecular to process scale. • Polymer recycling concepts discussed in a broader perspective, addressing market analysis, life cycle assessment, and socio-technical system innovation.