(193s) Thermal Ageing Performance of Polyolefins Under Different Temperatures

Thermoplastic polyolefin (TPO) membranes are widely used as commercial roofing solutions thanks to their characteristics such as toughness, chemical resistance and seal integrity. Heat stability of these products is of great interest as long lifetimes are required for this type of application. Accelerated tests are often used where materials are tested under elevated temperatures, in which unrealistic degradation may occur. Surface chemistry tracking method is employed to provide an alternative to mechanical testing, as well as a secondary metric to investigate the validity of the testing results. A comparison was made between the two tracking metric results under different temperatures that revealed the importance of selecting an adequate ageing temperature for comparing materials with different melting temperatures. Above the polymer melting temperature, the decrease in crystallinity allows more oxygen to diffuse into the polymer and may cause unrealistic failure, resulting in invalid comparisons under high testing temperatures.