Assessment of pro-oxidant activity of natural phenolic compounds in bio-polyesters

To assess the pro-oxidant activity of the considered natural phenolic compounds, thin films of PLA and PLA-based systems containing VA, FA and Th have been subjected to accelerated degradation in different environmental conditions: (i) water-medium hydrolysis, (ii) photo-oxidation upon UVB exposure and (iii) thermo-oxidation upon thermal treatment in oven. All obtained results pointing out that the considered natural compounds, at these high concentrations, exert a clear pro-oxidant activity in PLA during the water-medium hydrolysis and the photo- and thermo-oxidative degradation. Moreover, the VA, FA and Th can be considered as suitable pro-degradant additives for PLA, also in order to control the bio-polyester degradation times.