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

The design and synthesis of a new class of thermally-labile poly(ß-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(ß-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.