RESUMO O objetivo deste trabalho foi caracterizar os compósitos produzidos com o terpolímero acrilonitrila-butadieno-estireno (ABS) reforçados com fibras de polpa celulose modificadas com nanopartículas de sílica (SiO2). Primeiramente, as fibras foram modificadas utilizando o processo sol-gel, tendo como precursor da sílica o ortosilicato de tetraetila (TEOS). Adicionalmente, duas concentrações de TEOS e dois tempos de reação foram utilizados para produzir dois tipos de fibras modificadas, FT1 e FT2, logo depois, foi determinado o rendimento de cada processo de modificação. As fibras foram caracterizadas por meio da microscopia eletrônica de varredura (MEV), análise termogravimetria (TGA) e sua derivada (DTG). Depois da obtenção das fibras os compósitos de acrilonitrila-butadieno-estireno reforçados com 10 e 20% (m/m) de fibras de polpa celulose branqueada não modificadas (FNT) e modificadas com nanopartículas de sílica (FT1 e FT2) foram obtidos por extrusão e posteriormente por injeção, depois os compósitos foram caracterizados quanto à densidade, análise térmica (TGA/DTG), temperatura de deflexão térmica (HDT) e a temperatura de amolecimento VICAT. A adição de fibras, de modo geral, proporcionou incremento para a temperatura de deflexão térmica HDT e temperatura de amolecimento VICAT, sendo mais acentuado quando o teor de fibras passou de 10% para 20%. No entanto, o aumento do teor de fibras de 10% para 20%, em comparação ao ABS puro provocou diminuição da temperatura de início de degradação e provocou aumento da densidade.

ABSTRACT The aim of this study was to evaluate thermal properties of composites made with terpolymer acrylonitrile-butadiene-styrene (ABS) reinforced with silica nanoparticles (SiO2) modified cellulose. Primarily, the fibers were modified using the sol-gel process and the tetraethyl ortosilicate (TEOS) as precursor. In addition, two concentrations of TEOS and two reaction times were used to produce two types of modified fibers, FT1 and FT2 fibers, then was determined the yield of modification process. The fibers were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and its derivative (DTG). The acrylonitrile-butadiene-styrene composites reinforced with 10 and 20% (w/w) unmodified cellulose pulp fibers (FNT) and silica nanoparticles modified (FT1 and FT2) were obtained by extrusion process and subsequent injection. The composites were characterized in terms of density, thermogravimetric (TGA / DTG), thermal deflection temperature (HDT) and VICAT softening temperature. In general, the addition of fibers provided an increase for HDT and VICAT, being more pronounced when the fiber content increased from 10% to 20%. However, in comparison with ABS the increasing of fiber content from 10% to 20%, caused a decrease in Tonset and caused an increase in density.

AbstractThe paper aimed at evaluating the feasibility and the properties of a new product which combines wood veneer and high-density polyethylene (HDPE) from post-consuming plastic bags. Three HDPE amounts were evaluated: 150g/m2, 250 g/m2 e 350 g/m2. The boards were manufactured using a single-opening hot-press under such conditions: 140ºC, for 20 minutes and pressure of 1 N/mm2. It was found that the production of this kind of composite board is technically possible and relatively simple and they did not present any veneer delamination. The properties of the composite boards were quite similar or even higher to those found in LVL made using thermosetting resin. The higher the HDPE amount the higher the density of the composite board, which imparted significantly in mechanical properties. However, when the composite boards were evaluated under same density the effect of the HDPE amount affected only Janka hardness.