Dissolution-assisted routes for converting plastic waste into functional materials

Mixed plastic waste (MPW) presents persistent environmental and economic challenges due to low recycling rates, intrinsic polymer incompatibility, and limitations of conventional mechanical recycling. Dissolution-assisted recycling has emerged as a structure-preserving, non-carbonization pathway that selectively solubilizes polymers, enhances chain mobility, and enables the direct fabrication of functional materials from heterogeneous plastic waste streams. This review critically examines the principles, advantages, limitations, and emerging applications of dissolution-assisted plastic waste valorization, with a particular focus on polyolefin-rich waste, which accounts for approximately 60% of the total MPW stream. The fundamentals of dissolution–precipitation, solvent-mediated compatibility enhancement, and post-processing strategies—such as thermally induced phase separation, spin casting, annealing, and multilayer design—are systematically discussed. Dissolution-assisted processing enables the compatibilizer-free fabrication of homogeneous composite materials. A broad range of functional applications enabled by dissolution-assisted routes is consolidated, including free-standing superhydrophobic films, feedstock pellets, oleophilic and superhydrophobic membranes, trimodal filtration membranes, sorbents with swellable cavities, anticorrosive coatings, activated carbon composites, and antibacterial surfaces. Key challenges related to solvent selection, energy demand, scalability, and durability are identified, alongside future opportunities in green solvent systems, hybrid compatibilization strategies, and performance-based life cycle assessment. Overall, dissolution-assisted valorization is positioned as a promising platform for transforming MPW into high-value functional materials within circular economy frameworks.