Effects of O3 and NO2 on the Natural Weathering of Plasticized Poly(vinyl chloride)

摘要

The aim of this work was to study the natural aging of plasticized poly(vinyl chloride) (PVC) stabilized with epoxidized sunflower oil and Ca/Zn stearates. For that purpose, PVC samples were exposed in Algiers (hot Mediterranean climate) in two sites where the concentration of atmospheric pollutants (NO2 and O3) was known for 2 years. Site I contained NO2 and O3, and site II contained only NO2. Samples were taken off every four months and characterized (mechanical properties and chemical modifications). The results showed a drop in tensile properties and an increase in Shore D hardness. The UV-Visible spectra evidenced the formation of short polyenes. Chemical structures due to the degradation were evidenced by ATR and transmission FTIR spectroscopy. It was found that the combination of O3 and NO2 exerted the most deleterious effect.