Highly Degradable Polyester With Chemical and Thermal Stability Utilizing Oxidative Degradation of 2‐Thioethyl Ester

ABSTRACT Although degradability and stability are generally incompatible, polymers that degrade through nonnatural stimuli can exhibit high durability, even if they are highly degradable. 2‐Thioethyl ester can be degraded into carboxylic acid by the oxidation of sulfide to sulfone using nonnatural oxidant followed by the treatment with base. Polyesters containing the 2‐thioethyl ester structure are synthesized. After the sulfide group is quantitatively oxidized to sulfone by mCPBA, the sulfone polyester dissolves even in sodium carbonate solution via the base‐promoted β‐elimination. The one‐shot oxidative degradation of sulfide polyester is achieved by the treatment with hydrogen peroxide solution in the presence of sodium tungstate as a catalyst and sodium carbonate as a base. The oxidation of sulfide to sulfone occurs only at the surface of the polyester particles, and further oxidation takes place after the sulfone layer is removed via β‐elimination. Polyesters with the structure of 2‐thioethyl ester are stable during use, but can be converted to the monomer at the desired instant after use.