Electrochemiluminescence Monitoring on the Photodegraded Radicals from Aromatic Polymers

Monitoring on the radicals in the early stage of polymer degradation is essential to unveil the degradation mechanism and achieve rational management of polymers. However, it is challenging to provide a sensitive monitoring on the radicals in the early stage degradation of polymers, especially for the nonemissive radicals. In this contribution, we proposed electrochemiluminescence (ECL) to monitor the radical behaviors in the early stage degradation of aromatic polymers. It was disclosed that carbon-centered radicals were generated in the photodegraded polymers, facilitating the formation of hydroxyl and superoxide anion radicals. Accordingly, ECL intensities of the photodegraded polymers were continuously promoted with the prolonged phototreatment from 0 to 12 h. In comparison, obvious signals could only be detected after a long-term phototreatment by the conventional electron spin resonance measurements. Additionally, thermal treatment showed no profound effect on the ECL promotion for the aromatic polymers due to the different radical reaction pathways. Therefore, we have realized sensitive monitoring on the radicals in the early stage degradation of aromatic polymers, providing valuable information for the radical reaction mechanism of polymer degradation evolution.