Recent progress in the green synthesis, modification, and high-end applications of sulfone polymers (2015–2026)

Abstract

Sulfone polymers are amorphous aromatic thermoplastics in which each repeating unit contains a sulfone group connected to phenylene rings by aryl ether linkages. This architecture imparts high glass transition temperatures, resistance to oxidation and hydrolysis, dimensional stability, and transparency, and has established bisphenol A polysulfone (PSF), polyethersulfone (PES), and polyphenylsulfone (PPSU) as mainstays of the specialty engineering plastics market. Existing reviews consider sulfone polymers either as membrane materials or primarily from a synthetic perspective; the complete manufacturing chain from sulfur feedstock to a finished high-end component has not been examined systematically. This review covers literature published from 2015 to 2026 and is organized around this value chain. We first analyse the industrial state of the art by examining chlorosulfonation, the sulfuric acid and sulfur trioxide routes to 4,4′-dichlorodiphenyl sulfone, and one- and two-step solution polycondensation to PSF, PES, and PPSU. We conducted a comprehensive comparison of these process routes. The resulting bottlenecks define the central theme of the review: green synthesis. At the monomer stage, we assess solvent-free and recyclable-acid sulfonylation, sulfide oxidation with H₂O₂ and O₂/air, palladium-catalyzed C–H sulfonylation, and solid sulfur dioxide surrogates that valorise surplus industrial sulfur. At the polymer stage, we assess ionic-liquid and zwitterionic media, phase-transfer catalysis, AB-type self-polycondensation, continuous and process-intensified polymerization, melt polycondensation, and oxidative conversion of poly(arylene sulfide)s, and identify opportunities to integrate monomer-level and polymer-level green chemistry. Modification strategies, including blending, copolymerization, grafting, and stimuli-responsive functionalization, are then linked to the high-end applications that now drive demand: proton- and ion-exchange membranes, water treatment, gas separation, haemodialysis, and epoxy toughening. Finally, we identify the most promising strategies and current best-performing materials, analyze the origins of the remaining bottlenecks, and outline research priorities and translational pathways for moving these technologies from the laboratory to industrial deployment.