Ionic Liquids as Green Solvents: Emerging Roles in Sustainable Polymer Synthesis and Processing

Ionic liquids (ILs), a class of low-melting organic salts with negligible vapor pressure and high thermal stability, have emerged as versatile media in polymer science.Their tunable physicochemical properties enable their application as green solvents, catalysts, and functional additives in polymer synthesis and processing.In polymerization reactions, ionic liquids provide enhanced solubility for monomers and catalysts, improved reaction control, and the ability to tailor molecular weight and polymer architecture in free-radical, ionic, and ring-opening polymerizations.In polymer processing, ILs facilitate the dissolution and regeneration of biopolymers such as cellulose, improve polymer blending and composite fabrication, and act as plasticizers or processing aids to enhance mechanical and thermal properties.Furthermore, the recyclability and low volatility of ionic liquids support sustainable and environmentally benign polymer technologies.This review highlights recent advances, mechanisms, advantages, and challenges associated with the use of ionic liquids in polymer synthesis and processing.