Studying the impact of degradation of polyethylene tri-layer films under simulated climatic conditions, of North Africa, on their mechanical behaviour and thermal stability and lifetime is the main objective of this work. The films are produced by the co-extrusion technique which is used in several industrial applications such as the nuclear related applications. The climatic conditions such as temperature, solar radiation, wind, sand and humidity are crucial factors in the ageing process, degradation and lifetime of polymeric materials. At the molecular level, these conditions have severe structural modifications and oxidation in polymers which are the main mechanism of ageing. Polyethylene films have numerous industrial applications in which they are susceptible to such harsh environmental conditions. Samples in the form of polyethylene films of 180μm thickness are artificially aged at different conditions of temperature and humidity. Monitoring the degradation in physicochemical properties of polymer matrices used and their stabilizing additives is carried out by thermal analysis (DSC) and mechanical tests. The results revealed that the investigated climatic conditions have essential deteriorative effects on the performance of the film. The correlation between the modification in the material structure and the degradation in the film properties is discussed.
The thermal and mechanical behaviour of structural steel piping systems
