Gerenciamento e destinação final para componentes automobilísticos em Polipropileno com aplicação em filamentos para impressora 3D

Abstract

The PP (polypropylene) is a polymer widely used in the automotive industry for internal and external components of vehicles. Mineral fillers are usually incorporated into its structure in order to improve the mechanical properties of the material, improve the compaction of injected parts, reduce the cost of raw materials, etc. These fillers are then incorporated into the PP, generating composites. Talc is one of the most widely used minerals in the production of vehicle components. Currently, an automotive vehicle has around 70% of its final parts made up of plastic parts, the vast majority of which are made of PP/talc. The objective of this study is to analyze and reduce the volume of waste generated by an automotive company in the southern region of Rio de Janeiro, particularly due to the disposal of automotive components made omf PP reinforced with talc. Automotive waste was collected and reprocessed to obtain test specimens through grinding and injection molding. Three different PP/talc composites (PP/20% w/w, PP/30% w/w, PP/40% w/w) were used, and extrusion and injection molding were performed to prepare the specimens that were applied in mechanical tensile and flexural tests. Fourier transform infrared spectroscopy (FTIR), determination of the melt flow index, differential scanning calorimetry (DSC), determination of density, scanning electron microscope (SEM) and optical microscope (OM) were also performed. The DSC analysis showed an increase in the crystallinity of the sample as the filler content in the matrix increased, improving the mechanical properties by acting as a nucleating agent for the PP, increasing the interaction (compatibility) between the talc/PP interfaces. Its melt flow index showed oscillatory behavior due to the increase in the talc content in the matrix, but remained satisfactory compared to the manufacturer's data sheet. The FTIR analysis showed spectra with peak variations attributed to the percentage of talc inserted in the PP matrix, that is, the higher the percentage, the greater the intensity of the peaks, which will influence the crystallinity of the material without negative impacts. The micrographs obtained by MEV and MO revealed a rough appearance of the material in which there was no interference in the printing of the filament. After analyzing the data obtained, variations were noted in the results of the three composites, but the results remained within the values specified by the manufacturer, and for PP /20% m/m, greater similarity and less variation were noted in comparison with the manufacturer's data. In the present study, it is concluded that PP /20% m/m filaments from the reprocessing of automotive components are viable options for reducing the use of virgin PP, thus reducing the volume of segregated components, possible environmental impacts and the possibility of offering more accessible products to society. For the other percentages (PP/30% m/m, PP/40% m/m), it is also possible to recycle and apply them in other injection processes. Finally, PP/talc from discarded parts in the automotive industry is a sustainable option and can be reprocessed/reused for other purposes.