Interaction between agrochemical contaminants and UV stabilizers for greenhouse EVA plastic films

Research was conducted to evaluate how solar radiation, agrochemical contamination, and different light stabilizer systems influence the mechanical properties of ethylene-vinyl acetate copolymer (EVA/C) based films suitable for crop protection. Three independent outdoor trials were performed at the experimental field of the University of Bari (Italy) in 2006, 2007, and 2008. During each trial each film type was installed in the field as new covering of two low tunnels: one of the tunnels was periodically sprayed inside with agrochemicals containing sulfur, chlorine and iron, while the other one, not sprayed, was used as control. Besides, artificial photoaging tests were carried out on the films in laboratory. The research showed that the different light stabilizer systems influenced the mechanical behavior of the films in the presence of the progressively absorbed agrochemicals. An improved resistance to the agrochemicals was recorded for the EVA/C films stabilized with aminoether type hindered amine light stabilizer (NOR-HALS) and ultra violet filter.