Chemiluminescence of photo-irradiated polypropylene containing various additives

Commercial isotactic polypropylene films containing various additives, namely a hindered phenol (BHT), an UV absorber (Tinuvin 326), a hindered piperidine (Sanol LS 770), and mixture of BHT and Sanol were photo-irradiated with or without a glass filter at ambient temperature, and chemiluminescence spectra of the films were measured. The chemiluminescence intensity of the photo-irradiated PP films increased with irradiation time, and the shape and the intensity were noticeably affected by the nature of the additives. In the photo-irradiated PP films containing BHT, an additional new peak was observed at ca 80–100°C, and the intensity of the new peak was remarkably enhanced by the combined use of BHT and Sanol. From the results obtained the origins of the chemiluminescence sources were discussed.