Preparación de materiales compuestos de matriz epóxica reforzados con Tungstato de Aluminio y su caracterización térmica y mecánica

Abstract

This work is intended to use aluminum tungstate nanoparticles (Al2W3O12), that exhibit a low positive thermal expansion, aiming to reduce and control the coefficient of thermal expansion (CTE) of the epoxy resin. In order to achieve this goal, a methodology was developed to disperse Al2W3O12 filler into the matrix using an ultrasonic probe and obtain composite specimens without defects. Moreover, the reduction of the particle size of Al2W3O12 in a planetary ball mill played an important role, because this process decreased the diameter of the agglomerates to submicronic dimensions (~312 nm), with no alterations in its crystalline phase. This promoted a better dispersion of particles and avoided the sedimentation thereof inside the matrix. Afterwards, the composites were prepared using 2,0; 3,0; 4,0; 5,0 and 6,0 mass % of the filler that correspond to 0,5; 0,7; 1,0; 1,2; 1,4 vol. %, respectively. The CTE of each composite was determined by thermomechanical analysis, reaching reductions up to 9 % on this property for the composite reinforced with 4,0 mass % of Al2W3O12. The last one was characterized by tensile test, revealing that the Young modulus, ultimate tensile strength and ductility were not changed by the incorporation of the Al2W3O12 particles. Likewise, the thermal properties (onset degradation temperature and glass transition temperature) of the epoxy resin were not affected, as verified by thermogravimetric analysis and differential scanning calorimetry, for all the ceramic loadings