Polymer composites for the automotive industry: characterisation of the recycling effect on the strain rate sensitivity

In this paper, the mechanical response of two composites-based polypropylene (PP) is studied. High strain rate tests as well as quasi-static uniaxial tests were performed. Dynamic loadings were carried out using the Split Hopkinson Pressure Bar. Materials used consist of an unfilled high-impact PP (hiPP) and a talc-filled hiPP. For each of these two materials, the recycling effects on the stress–strain response for both quasi-static and dynamic loading were studied. The degradation of the mechanical response due to recycling is then characterised for a wide range of loading rates for both materials. Scanning electron microscopy analyses have been achieved in order to quantify recycling and strain rate effects and also to correlate them with the microstructure evolution for a better understanding of the mechanisms involved in the recycling process and in the dynamic loading. This study has led to a preliminary understanding of the recycling effects, particularly for impact loadings.

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