Motivated by environment preservation, the increased use of eco-friendly materials such as biodegradable polymers and biopolymers has raised the interest of researchers and the polymer industry. In this approach, this work aimed to produce bioblends using poly (lactic acid) (PLA) and high-density biopolyethylene (BioPE); due to the low compatibility between these polymers, this work evaluated the additional influence of the compatibilizing agents: poly (ethylene octene) and ethylene elastomer grafted with glycidyl methacrylate (POE-g-GMA and EE-g-GMA, respectively), polyethylene grafted with maleic anhydride (PE-g-MA), polyethylene grafted with acrylic acid (PE-g-AA) and the block copolymer styrene (ethylene-butylene)-styrene grafted with maleic anhydride (SEBS-g-MA) to the thermal, mechanical, thermomechanical, wettability and morphological properties of PLA/BioPE. Upon the compatibilizing agents’ addition, there was an increase in the degree of crystallinity observed by DSC (2.3–7.6% related to PLA), in the thermal stability as verified by TG (6–15 °C for T_D10%, 6–11 °C T_D50% and 112–121 °C for T_D99.9% compared to PLA) and in the mechanical properties such as elongation at break (with more expressive values for the addition of POE-g-GMA and SEBS-g-MA, 9 and 10%, respectively), tensile strength (6–19% increase compared to PLA/BioPE bioblend) and a significant increase in impact strength, with evidence of plastic deformation as observed through SEM, promoted by the PLA/ BioPE phases improvement. Based on the gathered data, the added compatibilizers provided higher performing PLA/BioPE. The POE-g-GMA compatibilizer was considered to provide the best properties in relation to the PLA/BioPE bioblend, as well as the PLA matrix, mainly in relation to impact strength, with an increase of approximately 133 and 100% in relation to PLA and PLA/BioPE bioblend, respectively. Therefore, new ecological materials can be manufactured, aiming at benefits for the environment and society, contributing to sustainable development and stimulating the consumption of eco-products.

Poly(ethylene-octene) grafted with glycidyl methacrylate (POE-g-GMA) and ethylene elastomeric grafted with glycidyl methacrylate (EE-g-GMA) were used as impact modifiers, aiming for tailoring poly(lactic acid) (PLA) properties. POE-g-GMA and EE-g-GMA was used in a proportion of 5; 7.5 and 10%, considering a good balance of properties for PLA. The PLA/POE-g-GMA and PLA/EE-g-GMA blends were processed in a twin-screw extruder and injection molded. The FTIR spectra indicated interactions between the PLA and the modifiers. The 10% addition of EE-g-GMA and POE-g-GMA promoted significant increases in impact strength, with gains of 108% and 140%, respectively. These acted as heterogeneous nucleating agents in the PLA matrix, generating a higher crystallinity degree for the blends. This impacted to keep the thermal deflection temperature (HDT) and Shore D hardness at the same level as PLA. By thermogravimetry (TG), the blends showed increased thermal stability, suggesting a stabilizing effect of the modifiers POE-g-GMA and EE-g-GMA on the PLA matrix. Scanning electron microscopy (SEM) showed dispersed POE-g-GMA and EE-g-GMA particles, as well as the presence of ligand reinforcing the systems interaction. The PLA properties can be tailored and improved by adding small concentrations of POE-g-GMA and EE-g-GMA. In light of this, new environmentally friendly and semi-biodegradable materials can be manufactured for application in the packaging industry.

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.