Marine Biodegradation of Poly(butylene succinate) Incorporating Disulfide Bonds Triggered by a Switch Function in Response to Reductive Stimuli

Although poly(butylene succinate) (PBSu) is degraded in compost and soil, it does not undergo degradation in the ocean. This study incorporated a switch function into PBSu to release low-molar-mass compounds that microorganisms can metabolize to enable biodegradation in ocean environments. The disulfide bonds in poly(butylene succinate- co -butylene dithioglycolate) (PBSDT) undergo reductive degradation in an environment with low oxidation–reduction potential (ORP), such as marine sediments. It acts as a switch to initiate PBSDT biodegradation. The reduced degradation compound, thioglycolate-butylene-succinate-butylene-thioglycolate, showed high biochemical oxygen demand (BOD) biodegradability. In contrast, PBSDTs had low BOD biodegradability under conditions of high ORP. In addition, the high-molar-mass PBSDT was molded into a film for experiments in mechanical strength.