This work investigated the effect of thermo-oxidation aging in blends of copolymer polypropylene (PPc)/recycled copolymer polypropylene (PPcr) from industrial container waste, coded as PPc/PPcr blends. All compounds were melt extruded, and the injection molded specimens were characterized by mechanical properties (tensile and impact), Fourier-transform infrared spectroscopy (FTIR), melt flow index (MFI), contact angle, heat deflection temperature (HDT), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). FTIR spectra presented bands related to the hydroperoxides and carbonyl groups, as resulted from thermo-oxidation aging. The contact angle decreased upon a thermo-oxidation aging influence, corroborating the FTIR spectra. PPcr presented higher MFI as a consequence of reprocessing. Impact strength and elongation at break were quite sensible to the thermo-oxidation aging influence and were progressively reduced upon increased time, whereas tensile strength, elastic modulus, and HDT only slightly changed. SEM images of PPc presented a higher quantity of pulled-out particles, resulted from a lower interaction between phases, i.e., polypropylene and ethylene/propylene. From the impact strength and toughness data, proper dissipation energy mechanisms were found in PPc/PPcr blends. Summing up, using PPcr contributed to minimize properties’ losses, which may be related to the stabilizer agents, whereas the described results presented great potential for the PP market, while contributing to the sustainable environment.

The practice of recycling over the years has been increasingly encouraged, with the aim being the manufacturing of materials that contribute to sustainable development. In light of this, the present work evaluated the potential of mixtures of polystyrene (PS)/recycled copolymer polypropylene (PPr), using styrene-(ethylene/butylene)-styrene (SEBS) as a compatibilizing agent. Initially, the mixtures were prepared in a co-rotational twin-screw extruder, and, afterwards, the extruded granules were molded by injection. The properties of torque rheometry, impact strength, tensile properties, differential scanning calorimetry (DSC), heat deflection temperature (HDT), and scanning electron microscopy (SEM) were evaluated. The formulation PS/PPr/SEBS (70/20/10 %wt.) demonstrated an increase in viscosity, corroborating with an increase of 123% and 227% in the elongation at break and impact strength, respectively, compared to neat PS. Though the elastic modulus and tensile strength suffered losses, the reduction was not drastic. Furthermore, the addition of a semi-crystalline recycled material in the amorphous matrix (PS) contributed to an increase in thermomechanical strength, as seen in the HDT. The morphology revealed that SEBS is effective in making PS/PPr mixtures compatible because the dispersed phase is well adhered to the PS matrix and promotes greater morphological stability. Thus, it is possible to add value to discarded material and reduce the costs of the final product, which can reduce pollution.

A produção de materiais ecológicos está sendo incentivada, visando minimizar os impactos ambientais e promover uma maior sustentabilidade. Portanto, esse trabalho, teve como objetivo desenvolver biocompósitos de biopolietileno (BioPE)/farinha de madeira (FM), utilizando como compatibilizante o polietileno enxertado com anidrido maleico (PE-g-MA). Os biocompósitos foram preparados em uma extrusora de rosca dupla corrotacional e moldados por injeção. As propriedades de resistência ao impacto Izod, resistência à tração, Dureza Shore D, Temperatura de Deflexão Térmica (HDT) e absorção de água foram investigadas. A resistência ao impacto aumentou quando o biocompósito BioPE/FM foi compatibilizado com PE-g-MA. Esse acréscimo foi mais expressivo para 10% de PE-g-MA com alto grau de enxertia de anidrido maleico, indicando um maior nível de interação entre as fases. Os biocompósitos BioPE/FM/PE-g-MA apresentaram propriedades de módulo elástico, resistência à tração, dureza Shore D e HDT aprimoradas, em comparação ao biocompósito não compatibilizado. Um aspecto importante foi a redução da absorção de água para os biocompósitos compatibilizados com PE-g-MA, sugerindo um maior efeito barreira para a difusão de umidade. Do ponto de vista do grau de enxertia de anidrido maleico no PE-g-MA, em geral, a resistência ao impacto foi a propriedade mais sensível. Os resultados indicam que a farinha de madeira é um resíduo com potencial para ser reaproveitado no desenvolvimento de biocompósitos.