enhancing photostability of pvc films using phenolic azanylylidene compounds

One of the biggest environmental issues with pvc polymer films is uv photodegradation. in this research, three azanylylidene compounds were prepared and filled as homogeneous and heterogeneous aromatic organic in 0.5 % concentration within the pvc to investigate their photodegradation effect on the polymer. infrared spectroscopy and proton nuclear magnetic resonance confirmed the chemical composition of antioxidant phenolic azanylylidene compounds. concentrated uv radiation was applied to examine the pvc polymer films for 300 h, divided into 100 h intervals. to determine carbonyl, hydroxyl, and polyene group absorption coefficients, the pvc polymer films’ infrared spectrum was measured before and after irradiation. the absorption coefficients of these groups decreased by adding those azanylylidene additives. additionally, the weight loss of blank and embedded pvc films prior to and after irradiation was measured to assess photodegradation. comparing with the unmodified pvc film, the modified ones showed less weight loss. sem images showed that azanylylidene-modified pvc polymer films had significantly less surface damage than plain film, indicating improved stability. x-ray mapping was used to assess azanylylidene compound distribution in pvc polymer films; ratios of some elements were changed, indicating that the additives prevented photo-oxidative decomposition. energy-dispersive x-ray (edx) analysis is also applied to detect the elements of pvc film before and after irradiation. the viscosity and molecular weight of all polymeric sheets are measured. the plain polymer’s molecular weight decreased significantly with increasing irradiation time, while the modified polymer’s molecular weight decreased less. the filled compounds worked as stabilizers that slowed pvc chain degradation.