The aim of this work is to study the natural ageing of rigid polyvinyl chloride (PVC) used in building and construction areas. For that purpose the PVC bars have been exposed in Algiers for 24 months in three sites where the concentrations of atmospheric pollutants (NO_x, O_3, hydrocarbons) are known. Samples were taken every three months. The evolution of mechanical properties was followed by tensile and hardness tests whereas the modification structure of polymer was followed by Fourier transform infrared spectroscopy (FTIR) and UV-visible spectroscopy. The results have shown a little drop in strain at break and stress at break, whereas hardness remains practically constant. IR and UV- visible analysis have shown apparition of chemical structures due to the polymer degradation (carbonyl and hydroperoxide groups and polyenes) since the first months of exposure in the three sites.
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