This thesis investigates the thiocarbonyl addition–ring opening (TARO) polymerization of dibenzo[c,e]oxepin-5(7H)-thione (DOT) to synthesise degradable polymers. Initial attempts involved free radical and reversible addition-fragmentation chain transfer (RAFT) polymerization for the synthesis of DOT–homopolymers. Unfortunately, this did not produce the desired results of high conversion and good yields. Subsequently, DOT–homopolymers were synthesised successfully through cationic ring-opening polymerization (CROP), resulting in a fully degradable polymer that yielded a thioester isomer of DOT upon degradation under mild conditions. Optimized polymerization conditions were achieved using the anhydrous non-polar solvent toluene and BF₃.Et₂O as an initiator.

The study then explored the optimization of DOT copolymerization using atom transfer polymerization (ATRP) with a selection of acrylic comonomers, with a focus on producing water-soluble degradable bottle brush copolymers. While copolymers with selectively degradable backbone thioesters were successfully synthesised, the polymerization also led to the Cu(I)-catalysed dethionation of DOT to its (oxo)lactone analogue, limiting the thioester content in the polymer. However, under anhydrous conditions, the side reaction was minimized and provided degradable copolymers with higher thioester content.

Additionally, PEG acrylate and di(ethylene glycol) acrylamide-based copolymers/diblock containing backbone thioesters were synthesised through RAFT radical ring-opening copolymerization for the formation of degradable micelles for potential drug delivery applications.