Weathering of HDPE in Rio de Janeiro city

The action of weathering on the mechanical and thermal properties of high density polyethylene (HDPE) without aditives in the atmosfere of Rio de Janeiro City was studied. After about 1800 hours of exposition time it was observed that degradation process was very fast and can be seen in some mechanical parameters. It was observed an increasing of 20% of elastic modulus. The stress at yield increased slightly and elongation decreased, Both, stress and elongation at break diminished. The elongation showed a decreasing about 90%. The impact resistance presented a loss of 50%. The molecular weight also decreased.