抄録
Since two decades unfilled and filled high impact polypropylenes have been used increasingly in automobile applications. The current economical and environmental contexts compel the car industry to focus their research on the recycling process of these materials. Of course, this process intervenes after a life cycle of use so degradation occurred due to oxidants, pollutions, loadings, etc. The studied materials are composed of polypropylene for matrix phase, EPDM or EPR as elastomeric nodules and talc as fillers. Therefore this study deals as well with recycling process effect and pollution effects on mechanical properties of unfilled and talc-filled high impact polypropylene. The recycling process is simulated by a six times reprocessing of virgins materials and the life cycle simulation is made by an adding of pollutants as engine oil and windshield washer fluid during the first extrusion process. Interactions between these products are also studied. In order to characterize the recycling and pollution effects, tensile test for small strain domain were conducted. Evolutions of Young modulus and yield stress are quantified in order to study the degradation occurred during recycling and pollution processes. Physical explanations are also proposed to elucidate these effects. Some post mortem SEM observations are made in order to confirm experimental observations on these effects on the microstructure.
