Radical Departure: Thermally-Triggered Degradation of Azo-Containing Poly(β-thioester)s

The design and synthesis of a new class of thermally-labile poly­(β-thioester)­s is reported. Aliphatic azo linkages were incorporated into the main chain of the polymers to allow for degradation to lower molecular weights upon heating. These polymers displayed a temperature-dependent degradation profile with a significant increase in decomposition rate as the temperature was raised from 60 to 95 °C. This approach was further extended to prepare amphiphilic triblock copolymers containing poly­(β-thioester)­s and poly­(ethylene glycol) (PEG). The resulting block copolymers were capable of self-assembly into micelles in water. Moreover, the assembled nanoparticles underwent dissociation as a result of exposure to heat.