A Comparative Study of Polymethacrylates Featuring Discrete Oligo(ethylene sulfide), Oligo(ethylene sulfoxide), and Oligo(ethylene sulfone) as Side Chains for Antifouling Applications

Thioethers can be oxidized to sulfoxides and sulfones, and such transformation enables facile access to side chains with different extents of oxidation for creating multifunctional sulfur-containing polymers. Herein, a series of discrete oligo(ethylene sulfide)-derived monomers and their corresponding oxidized monomers are synthesized by iterative synthesis, affording discrete oligomers with two or three repeat units. Reversible addition−fragmentation chain transfer (RAFT) polymerization of these monomers gives well-defined polymers featuring discrete thioether, sulfoxide, and sulfone oligomers as side chains, and their thermal stability and glass transition temperature (T_g) are analyzed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The antifouling properties of these materials are challenged by antifouling assays against the attachment of proteins, bacteria, and human blood cells. Furthermore, the polymer with sulfoxide side chains is water-soluble and exhibits low cytotoxicity against mouse fibroblast cells (NIH/3T3), which holds potential as an alternative hydrophilic material to mitigate severe fouling.