Realizado em 09 de dezembro de 2020
Horário: Das 16h às 17h30 (Horário de Brasília)
Resumo: The use of natural fibrous materials has gained large interest of application in various sectors in order to find solutions to replace the use of conventional materials. Natural fibers also allow the weight reduction of the final composite materials, due to their lower density, in comparison to synthetic fibres. The replacement of synthetic fibres by natural ones allows lower fuel consumption, which is an important factor for environmental sustainability, due to reduction of greenhouse gases emission. Also, the natural fibrous materials are also biodegradable and recyclable, when used with thermoplastic matrices, characteristics which are equally important for sustainability. Besides these advantages, low cost and lower health hazards, comparing to synthetic fibres, are also to be considered. However, the combination of natural fibres with polymeric materials has some constraints related to the compatibility between both materials. Vegetal natural fibres are composed mainly by cellulose and hemicellulose, which are hydrophilic, and lignin on the surface, which is hydrophobic. This causes poor wettability of the natural fibres by polymers and, consequently, weak compatibility and adhesion at the interface between both materials. In this context, surface treatments on these materials for partial extraction of lignin become important to improve the compatibility with polymeric materials. depending of the applied surface treatment and its concentration, different mechanical properties can be modified. In this context, an understanding of what occurs in the morphological structure is fundamental.