Combined UV-irradiation and pyrolysis-GC/MS approach for evaluating the deterioration behavior of ethylene vinyl acetate

Ethylene vinyl acetate (EVA), commonly used to encapsulate photovoltaic (PV) modules, deteriorates on prolonged exposure sunlight. In this work, fresh and deteriorated EVA samples prepared by UV irradiation (500 W m−2) over different periods (0–168 h) are characterized conventional elemental analysis, microscopic observations, Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry. To the best of our knowledge, is first work employ pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) micro-UV combined Py-GC/MS (UV/Py-GC/MS) investigate deterioration behavior EVA, using in-situ identification gases liberated during irradiation, such as H2O, CO2, ketones, acetic acid, lactones. addition, thermal stability aging confirmed evolved gas analysis-mass (EGA-MS). UV/Py-GC/MS revealed that acetaldehyde, acetone, γ-butyrolactone, succinic anhydride, cyclobutanone produced irradiation. identified cyclopentanone, citraconic γ-valerolactone, from samples, which suggested presence ketone lactone structures in EVA. This establishes usage a promising method greater detail. These findings may contribute superior understanding breakdown PV modules lead development UV-resistant encapsulating materials.