Used as a polymeric chain transfer agent in controlled radical polymerization, particularly in reversible addition-fragmentation chain transfer (RAFT) processes. Enables precise molecular weight control and narrow polydispersity in the synthesis of block and graft copolymers. Its methoxy-terminated polyether chain enhances solubility in polar solvents and improves compatibility with hydrophilic monomers. Commonly applied in the development of functional polymers for coatings, drug delivery systems, and nanomaterials. The cyano and phenylthio groups contribute to high chain transfer efficiency and stability during polymerization.