Production of Eco-Sustainable Materials: Compatibilizing Action in Poly (Lactic Acid)/High-Density Biopolyethylene Bioblends

Abstract

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 TD10%, 6–11 °C TD50% and 112–121 °C for TD99.9% 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.

Use of crosslinking agent to produce high‐performance PLA/EVA blends via reactive processing

“…As previously reported, [ 17,34,35 ] PLA displays a single decomposition step, around 270–414°C. In EVA, there are two weight loss events, characteristic of the decomposition of the vinyl acetate group and the ethylene present in EVA, [ 23,36 ] with peak degradation temperatures around 353°C and 471°C, respectively.…”

“…[2,12,30] Figure 10 shows the elastic modulus of PLA and the PLA/EVA blends. As previously reported, [17,34,35] PLA has a high elastic modulus, approximately 2030 MPa, characteristic of its stiffness and poor toughness. Upon addition of 30% EVA, the resulting PLA/EVA blend displays a decreased elastic modulus (approximately 1180 MPa) due to the elastomeric behavior of EVA.…”

“…Figures 9 and 12 show that PLA has the highest tensile strength, approximately 55 MPa, being considered a fragile material and requiring higher loads to deform and rupture. [ 35 ] With the addition of 0.2 phr DCP, the tensile strength reduces compared to the PLA/EVA blend without DCP. The tensile strength increased with the DCP content, with higher values for the blend with 1.0 phr DCP (29 MPa).…”

“…This increment is likely due to the interactions between vinyl acetate and the chemical groups of PLA, combined with the elastomeric bahavior of EVA. [17,35,45] Upon the addition of DCP to PLA/EVA, there is greater surface uniformity, depending on the amount of DCP. The increase in surface uniformity is noticeable for DCP levels of 0.6, 0.8, and 1.0 phr, in agreement with the impact experiments.…”

Jatobá wood flour: An alternative for the production of ecological and sustainable PCL biocomposites

“…[5][6][7] The academic community and the industrial sectors have invested efforts to use natural fibers during development of hybrid materials, giving rise to the so-called ecocomposites or biocomposites. 8,9 Currently, ecological composites are being extensively investigated with polymers with lower environmental impact, such as poly (lactic acid) (PLA), polyhydroxybutyrate (PHB) and polycaprolactone (PCL), [10][11][12][13][14][15] aiming at sustainable development.…”