Lecture
This lecture covers the photodegradation of polymers, focusing on the characteristics of various polymers, their absorptivity to the solar spectrum, and the primary and secondary photodegradation processes involved. It also discusses the photostabilization strategies used to prevent light absorption and deactivate excited states of chromophores, leading to the development of UV screeners, UV absorbers, excited state quenchers, and free radical scavengers. The lecture delves into the effects of stabilizers on the photostability of poly(propylene) and the mechanisms behind secondary photodegradation processes. Additionally, it explores reactions due to dyes and pigments, emphasizing singlet oxygen sensitization and photo-oxidation by semiconducting pigments.