Global attention increasingly focuses on innovative recycling and upcycling strategies to advance polymer sustainability and reduce plastic waste. Reactive melt extrusion (RME) enables solvent-free polymer deconstruction and functionalization in the melt state, aligning with the principles of green chemistry: minimizing waste, avoiding solvents, and reducing energy consumption. RME leverages legacy polymer processing infrastructure, i.e., single- and twin-screw extruders, to empower rapid technology adaptation for research and industrial applications. This Perspective highlights the development of RME for rapid polymer deconstruction, emphasizing broad applicability for thermoplastics and thermosets that are derived from both chain-growth and step-growth polymerization processes. In addition, the RME platform offers rapid upcycling of plastic waste into vitrimers and other value-added materials with renewed service life, overall promoting polymer sustainability. Emerging in situ chemo-rheological characterization techniques deconvolute shear, temperature, and residence time effects during RME deconstruction/upcycling, unveiling key mechanistic insights into evolving rheological behavior during chemical and structural transformation. Finally, a perspective on emerging research directions aims to expand RME as a more versatile platform for polymer deconstruction, upcycling, and sustainability.
Nettles et al. (Mon,) studied this question.