Examinando por Autor "da Costa García Filho, Fabio"

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Development and characterization of WPCs produced with high amount of wood residue
(Elsevier, 2020-06-19) Dantas Viana Barbos, Josiane; Batista Azevedo, Joyce; da Silva M. Cardoso, Pollyana; da Costa García Filho, Fabio; Gómez-del Río, Teresa
tIn this work, high levels of wood residue were incorporated into high density polyethylene(HDPE). The composite processing was carried out in a twin screw extruder. Due to the largeamount of solid charge, adaptation of the equipment was necessary. Wood polymer com-posites (WPCs) with 60, 65 and 70% wood residue were obtained. In order to use compositesin applications such as profiles for application on floors, an analysis of the fatigue strengthof the composites was performed, as well as the water absorption capacity. The effect ofultra violet (UV) radiation on the surface of the composites was also evaluated using sim-ulation in a degradation chamber. There was a significant increase in the stiffness of thecomposites and a reduction in flexural strength. Due to the large amount of load, formationof agglomerates was observed, which reduced the impact resistance. In spite of the use ofcompatibilizers, it was observed a weak adhesion between the phases, which impaired inthe number of cycles under fatigue. When subjected to UV-degradation, the materials exhib-ited a small reduction in tensile strength. In general, the results indicate that the developedWPCs, considering applications in floors, presented some suitable properties such as rigid-ity and flexural strength, however, the processing conditions must be adequate for greaterinteraction between the phases.
Mechanical Properties Optimization of Hybrid Aramid and Jute Fabrics-Reinforced Graphene Nanoplatelets in Functionalized HDPE Matrix Nanocomposites
(2023-05-26) Oliveira Costa, Ulisses; da Costa García Filho, Fabio; Gómez del-Río, Teresa; Passos Rodriguez, Joao Gabriel; Tonini Simonassi, Noan; Neves Monteiro, Sergio; Cassiano Nascimento, Lucio Fabio
Natural lignocellulosic fibers (NLFs) have been used as a reinforcement for polymer matrix composites in the past couple of decades. Their biodegradability, renewability, and abundance make them appealing for sustainable materials. However, synthetic fibers surpass NLFs in mechanical and thermal properties. Combining these fibers as a hybrid reinforcement in polymeric materials shows promise for multifunctional materials and structures. Functionalizing these composites with graphene-based materials could lead to superior properties. This research optimized the tensile and impact resistance of a jute/aramid/HDPE hybrid nanocomposite by the addition of graphene nanoplatelets (GNP). The hybrid structure with 10 jute/10 aramid layers and 0.10 wt.% GNP exhibited a 2433% increase in mechanical toughness, a 591% increase in tensile strength, and a 462% reduction in ductility compared to neat jute/HDPE composites. A SEM analysis revealed the influence of GNP nano-functionalization on the failure mechanisms of these hybrid nanocomposites.