Desenvolvimento de compósitos híbridos de polietileno carregados com alumina e reforçados com fibra de vidro

• Autor(a) principal: Lins, Sergio Augusto Barcellos
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/8037
• topic: Polyethylene; Composite material; Hybrid composite; Fiberglass; Alumina; Polietileno; Material compósito; Compósito híbrido; Fibra de vidro; Alumina; Compósitos poliméricos; Plástico reforçado; CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA

In this investigation, composite materials made from high-density polyethylene (HDPE) and alumina, and from HDPE, alumina and fiberglass were developed aiming towards an improvement in its wear rate and thermal stability with the addition of alumina, as well as an improvement in stiffness and mechanical resistance with the addition of fiberglass. Alumina concentration employed ranged from 5% w/w to 10% w/w and fiberglass concentrations from 10% w/w to 30% w/w. For the hybrid composite materials, alumina concentration was maintained constant as the fiberglass concentration increased. Both composites were processed through extrusion method within a double-screw extruder with a temperature profile from feeding to dosing area of 160°/170°/180°/190°/200°/210°/215°/220°/225°/230° at a 600 rpm screw rotation. The composites properties were evaluated through a multi-analytical approach. The results pointed to a significant increase of the elastic moduli for the hybrid composite with higher inorganic filler content at the cost of a high decrease in toughness (from 25.2 MJ/m3 originally obtained with the raw polymer to 1.95 MJ/m3 for the higher filler concentration composite) alongside a slight decrease in impact resistance. Elastic moduli improvement was observed in both composites, hybrid and binary, being higher for the hybrid composites due to the addition of fiberglass. HDPE-Alumina composites presented a decrease in mechanical resistance whereas the hybrid composites have shown an increase of this value. Concerning thermal properties, the hybrid composites presented higher thermal stability than the HDPE-Alumina composites and a similar degradation temperature to the raw polymer. HDPE-Alumina composites were evaluated concerning wear rate and have shown an improvement of this property with increasing filler content. Micrographs pointed to a weak adhesion between alumina particles and the polymeric matrix. Overall, it was produced a polymer based material with considerably higher stiffness and mechanical resistance than that presented by the polyethylene. Alumina particles have also shown to improve the wear rate of the composite.