Fabricação e estudo do comportamento mecânico de corpos de prova de poliuretana (PU) reforçados com fibra de algodão (FA)

Abstract

The present work intend at the manufacturing and mechanical characterization of polyurethane (PU) composite derived from a blend of vegetable oils, supplied by the manufacturer KEHL, (AG201 Prepolymer + AG201 Polyol) with a ratio of 1: 1, reinforced with blades from cotton fiber (CF) by means of the tensile tests. The manufacturing process used is vacuum molding. A vacuum bag is made on a glass table, where the intercalation between cotton fiber and the resin happens at the time of the stacking of blades and after that, the removal of all air throught a vacuum pump, which was in operation for 24 hours, takes place, obtaining laminated composite plates of PU and CF. Thus, test specimens were fabricated with fiber orientations in 0 °, ± 45 ° and 90 °. After a manufacturing, the tests were performed in a universal test machine according to ASTM D3039 / D3039M - 14, which allows to evaluate the mechanical behavior from the composite in relation to the tensile test. Ultimately, the results were obtained using the amount of 7 layers from cotton fiber oriented at 0 °, ± 45 ° and 90 °. The composite showed a significant improvement in the mechanical properties, especially in the maximum tensile strength. The maximum tensile strength for neat PU is 41.73 MPa and for the composite is 84,841 MPa, however the deformation remained practically the same. The modulus of elasticity also increased in relation to that presented by neat PU.