The effect of UV light on luminescent blends

The use of conjugated polymer blends is an option to improve technological devices. The present work used a nitrile rubber (NBR) blend as a matrix and a conjugated polymer derived from polythiophene and/or polyfluorene. These materials were prepared and exposed to UV light (365 run) for different periods. The blends were characterized by luminescent properties (absorption and emission) and submitted to infrared spectroscopy and thermogravimetric analysis before and after exposure to the light. The results showed a good rubber protection for up to 7 h of exposure, before degradation of the conjugated polymer. Afterwards, a new band was observed in the UV-vis absorption, and the infrared spectra show Fied the formation of alcohols and/or peroxides. The thermogravimetric analysis of the three copolymers did not present significant changes compared to the beginning of the degradation and the shape of the curves. Therefore, we concluded that the NBR matrix was efficient in protecting the conjugated polymer for up to 7 h of exposure to light. (AU)