Papers by Wallisson Silva
In this study, blends of copolymer polypropylene (PPCop /recycled polypropylene (PPRec) from indu... more In this study, blends of copolymer polypropylene (PPCop /recycled polypropylene (PPRec) from industrial containers after consumption were evaluated in three different ratios (80:20, 60:40 and 40:60 wt.%). The blends were evaluated by melt flow index, torque rheometry and rheology in a dynamic oscillatory regime. The results from the melt flow index indicated that the blending of recycled material with PPCop causes a decrease in the molecular weight as compared to PPCop. By torque rheometry, it was verified that the blends showed improved processability in relation to PPCop. Also, the blends showed stability throughout the processing, indicating absence of degradation due to the process conditions used. By the dynamic-oscillatory regime tests, it was observed that, at low frequencies (<1 rad/s), the PPCop and the blends (PPCop / PPRec) demonstrated a Newtonian fluid behavior, whereas, at frequencies greater than 1 rad/s, a pseudoplastic fluid behavior was observed. The values of t...
Journal of Polymers and the Environment, 2021
Use of fiber reinforced composites derived from renewable sources has increased in recent years, ... more Use of fiber reinforced composites derived from renewable sources has increased in recent years, aiming at a balance between sustainability and technological development. This research sought to develop poly (lactic acid) (PLA)/poly (ε-caprolactone) (PCL) composites using wood powder (WP) as reinforcement. The composites were initially prepared in a co‐rotational twin‐screw extruder, and the extruded granules were then molded by injection. Mechanical properties (impact, traction, Shore D hardness), heat deflection temperature (HDT), differential scanning calorimetry, contact angle, and analysis with scanning electron microscopy were evaluated. ANSYS® computer simulation for mechanical performance of the materials was used to assess the performance of disposable cups. Impact strength for PLA/PCL bioblend and PLA/PCL/WP composites was higher than neat PLA. In addition, Shore D hardness, elongation at break, and HDT were on the same level as PLA, indicating that high WP concentrations did not severely compromise these properties. However, losses were observed in elastic modulus and tensile strength, and the PLA/PCL/WP composites increased the interaction with water, as reflected in the contact angle. From a practical standpoint, and as verified in the simulation, mechanical performance of the composites was satisfactory for the manufacture of disposable cups. The results are valuable for the area of recycling since it is possible to reuse and add value to a discarded material, thereby reducing costs and promoting sustainability.
Matéria (Rio de Janeiro), 2020
RESUMO Neste estudo, foram avaliadas blendas de polipropileno copolímero (PPCop)/polipropileno re... more RESUMO Neste estudo, foram avaliadas blendas de polipropileno copolímero (PPCop)/polipropileno reciclado (PPRec), proveniente de baldes industriais pós-consumo, em três proporções diferentes (80:20; 60:40 e 40:60% em peso). As blendas foram avaliadas por índice de fluidez, reometria de torque e reologia em regime dinâmico-oscilatório. Os resultados de índice de fluidez indicaram que a mistura de material reciclado com o PPCop promove uma diminuição da massa molar, em comparação ao PPCop. Por reometria de torque, verificou-se que as blendas melhoraram a processabilidade em comparação ao PPCop. Além disso, as blendas apresentaram estabilidade ao longo do processamento, indicando ausência de degradação para as condições de processos utilizadas. Por meio dos ensaios em regime dinâmico-oscilatório, observou-se que, em baixas frequências (< 1 rad/s), o PPCop e as blendas (PPCop/PPRec) apresentam um comportamento de fluido Newtoniano, enquanto que, para frequências maiores que 1 rad/s, ...
Sustainability, 2020
The practice of recycling over the years has been increasingly encouraged, with the aim being the... more 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 lo...
Engenharia no Século XXI – Volume 13, Feb 1, 2020
Modo de acesso: World Wide Web Inclui bibliografia 1. Engenharia 2. Educação.I. Título. CDD-620 O... more Modo de acesso: World Wide Web Inclui bibliografia 1. Engenharia 2. Educação.I. Título. CDD-620 O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos seus respectivos autores.
Materials Research Express, 2019
Materials Research Express, 2019
Research, Society and Development, 2021
A produção de materiais ecológicos está sendo incentivada, visando minimizar os impactos ambienta... more 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 apri...
Modo de acesso: World Wide Web Inclui bibliografia 1. Engenharia 2. Educação.I. Título CDD-620 O ... more Modo de acesso: World Wide Web Inclui bibliografia 1. Engenharia 2. Educação.I. Título CDD-620 O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos seus respectivos autores.
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Papers by Wallisson Silva