Desenvolvimento de compósito de poliuretana derivada de óleos vegetais com reforço de fibra de vidro

Abstract

Fiberglass reinforced composites are vastly used in many engineering applications, due to its combination of mechanical properties, low cost and ease of use. Fiberglass reinforced composites can be found in aerospace industry, surfboards and wind turbines, altough the main issue with this type of composites is the toxic chemicals released during the fabrication process. An alternative to this issue is replacing the matrix with castor oil polyurethane, which is biodegradable and is extracted from renewable sources, without the need of solvents in the manufacturing process. In this study a fiberglass reinforced composite made with castor oil polyurethane is developed. The fiberglass woven used is the E-glass, bi-directional (0° and 90°), 120g/m², from the supplier Fibertex. Two types of composites were manufactured: the first using the conventional polyester resin and the second using the castor oil polyurethane, applying high temperature and pressure. Three pressures (1,3, 2,6 and 3,9MPa) and two temperatures (70°C and 90°C) were studied. The mass fraction fiber/matrix of the composites was the same for all cases (40/60). After the composites were manufactured they were tested for flexural strength and their densities were measured. After testing, the samples were taken to the scanning electron microscope for the fracture analisys. It was observed that the increase in temperature during the fabrication resulted in a decrease of the flexural strength. Results showed that the samples fabricated using 70°C and 3,9MPa presented the greatest flexural strength, 756,1MPa. The greatest modulus of elasticity found was 45,1GPa, for the sample fabricated under 70°C and 1,3MPa. This shows that the composite proposed in this study is viable, considering that its mechanical properties were greater than those of the polyester matrix composite.