Material propertiesImpact of biodiesel sorption on tensile properties of PE-HD for container applications

In previous papers, we investigated the influence of biodiesel or diesel on mechanical properties of a high-density polyethylene (PE-HD) for tank applications using Charpy impact tests and dynamic-mechanical analysis (DMA). In this work, covering two more PE-HD materials, we extend our study to addressing the tensile properties, especially changes of Young's modulus, after immersion in biodiesel or diesel at 60 °C. As we cover sorption and desorption behavior, during desorption, i.e. storage at 60 °C in a circulating air oven, ageing or degradation phenomena were also observed and characterized in some detail using spectral reflectance measurements and FT-IR spectroscopy. The results obtained here support the concept of co-oxidation, i.e. the faster oxidation of the PE-HD matrix if the samples were previously saturated with biodiesel, itself easily oxidizable.