Obtenção e caracterização de compósito de PEBD com fibra de cana-de-açúcar in natura e modificada

Abstract

The increase in the study and development of polymeric matrix composites with vegetable fibers is due to the search to reduce energy consumption and the impacts on the environment. Among the vegetable fibers, the most commercialized and with extensive agricultural activity in Brazil are sugarcane bagasse fibers, due to its high harvest during practically the entire year, which facilitates its obtainment. Its use as reinforcement in thermoplastic composites of great economic and environmental interest. Thus, the main objective of this work was to produce composite specimens with a low density polyethylene matrix reinforced with different contents of in natura and modified sugarcane fibers, in order to evaluate their mechanical properties through the test of traction. Although the specimens are made by compression molding, through pressing on metal plates, the results obtained were satisfactory, managing to produce regular specimens and with a good dispersion of fibers in the polymer matrix, due to an efficient pressing process . However, the mechanical characterization of pure LDPE and composites reveals that with the increase of fiber content in the composites, the mechanical properties of tensile strength and elastic deformation decreased, with a decrease also in plastic deformation. With the exception of the composite containing 20% (m/m) of modified sugarcane fiber, which presented greater stiffness and strength than the composite with 15% (m/m) of modified fiber. Thus, with the increase in fiber content, the mechanical performance of the composite was impaired, due to the increase in the amount of stress concentrators in the system, which ended up reducing the material's strength and deformation.