Used as a bifunctional coupling agent in polymer chemistry, particularly in the synthesis of functionalized polymers and block copolymers. Its bromine end groups allow for controlled radical polymerization techniques such as ATRP (atom transfer radical polymerization), enabling precise molecular weight control and narrow polydispersity. The disulfide linkage provides a cleavable site under reducing conditions, useful in responsive or degradable polymer systems. Commonly applied in the development of smart materials, drug delivery carriers, and surface modification of nanomaterials where reversible bonding and tailored architecture are required.