Influ?ancia de estabilizantes na degrada?§?￡o foto-oxidativa de filmes de comp?3sitos de SWy-1/poli(?3xido de etileno)

摘要

Poly(ethylene oxide) (PEO) with SWy-1 montmorillonite and stabilizers (2-hydroxybenzophenone and tinuvin 770) composites were prepared by intercalation in solution method. The films of the composites were exposed to UV irradiation. The photodegradation products were monitored by FTIR (Fourier Transform Infrared Spectroscopy) and SEC (Size Exclusion Chromatography) method. The PEO pure showed higher degradation rate coefficients, kd , compared to the others samples. The system that showed the lowest value for the degradation rate coefficients (kd = 1.9×10–6 mol g –1 h –1) was the PEO/SWy-1 5% composite with 0.25% of tinuvin 770. In this case, the stabilization of the PEO matrix can be attributed to clay associated with tinuvin 770. The clay scatters and absorbs UV irradiation and tinuvin acts as a stabilizer of the HALS (hindered amine light stabilizers) kind.