Estudos das propriedades do compósito de poliuretano derivado de óleo vegetal com ATH e tecido de juta para uso aeronáutico

Abstract

The aeronautical industry uses polymers derived from petroleum and synthetic fibers, which are not biodegradable and require a large amount of energy in their production. The composite based on polyurethane derived from vegetable oil – PU – and jute fiber fabric comes from natural sources of raw material, is biodegradable and does not use volatile organic solvents. In an aeronautical accident, the burning of aircraft components generates heat, smoke and toxic gases, which can make rapid evacuation of persons impossible. Polymeric materials, when in contact with a heat source, have rapid heating, high release rate of combustible gases, short ignition times and high amounts of CO released. To minimize flammability problems of polymers, it is necessary to use flame retardant additives. Alumina trihydrate – ATH is a non-toxic inorganic mineral additive, that has flame retardant property. The ATH hydroxyls may react with isocyanate before reacting with polyol hydroxyls during the PU polymerization reaction. The objective of this study was to evaluate the possibility of using the PU/jute composite in aircraft cabin interior components, by means of flammability tests following the requirements RBAC 25 of the ANAC. Samples with different amounts of ATH were tested by the pass/fail test on the flammability test. Samples with ATH that met the flammability requirement, and without ATH, were tested by flexion and traction, and analyzed by SEM and TGA/DTG with FTIR, being checked for interference of ATH on the mechanical properties, composite microstructure and gases expelled in thermal degradation. The 38% mass ATH PU/jute composite sample met the aeronautical flammability requirement, and had the best mechanical properties, with 61.77 MPa bending stress, 4.18 GPa elastic modulus in bending, 41.78 MPa maximum tensile strength and 1.88 GPa modulus of elasticity. This sample showed traces of CO and Nox in the gases expelled from the thermal degradation of the TGA/DTG analysis with FTIR. It can be concluded that the material can replace the composite materials used inside aircraft cabin.