Preparation of Degradable and Sequence-Controlled Aliphatic Polysulfones by Group Transfer Radical Polymerization

Abstract

The incorporation of sulfur atoms into polymer backbones for the synthesis of sulfur-containing polymers, such as aliphatic polysulfones, not only enhances degradability but also imparts many distinctive properties to these materials. Traditional synthetic methods encounter substantial challenges in achieving sequence-controlled aliphatic polysulfones with high molecular weights (MW), which significantly limits their applications. We report a novel approach for synthesizing aliphatic polysulfones using the strategy of sulfonyl radical-mediated group transfer radical polymerization (GTRP). This protocol employs a practical SO2-free pathway and produces a series of ABC sequence-defined high-MW polymers (up to 199 kg/mol). The resultant aliphatic polysulfone exhibits remarkable full-degradability at ambient temperature under strong basic conditions, and offers optical properties—including refractive index and Abbe number—comparable to those of commercially utilized polycarbonate. Additionally, density functional theory (DFT) calculations have been performed to corroborate the non-desulfonylative Smiles rearrangement mechanism implicated in the GTRP process.