STUDY OF THE MECHANICAL RESISTANCE OF A POLYMERIC MATRIX COMPOSITE WITH ALUMINUM ADDITION
Biomaterials, Bone Cements, PMMA, Alumina, Polymer matrix composite
Currently, research for the development of biocompatible materials has been widely developed. These materials, also known as biomaterials, are used in the medical field in order to treat, replace or repair biological systems (tissues and / or organs) partially or totally. In the area of orthopedic surgery, bone cements, besides the use for fixation of implants, are applied in the repair of bone failures resulting from fractures caused by high energy trauma, as in the case of accidents involving automotive vehicles and / or human aging, in the face of osteoporosis, which is a disease characterized by the reduction of the mineral part of bones, making them more fragile, and consequently, more susceptible to fractures. Bone cement based on polymethylmethacrylate (PMMA) is already widely applied in the field of orthopedic surgery; In this work the effect of the addition of alumina (Al2O3) on the polymeric matrix (PMMA) on the mechanical properties, mainly flexural strength, was studied. The composite formed by PMMA and Al2O3, besides its possible applicability in the orthopedic area, will allow a reduction of cost, since the alumina is abundant in nature. For the development of this work the powders of PMMA and alumina were characterized, and to obtain the composites the polymer mixtures (powder) were carried out in the presence of the liquid reducer (monomer) with addition of alumina, in the proportions of 0.5 %, 1% and 2% by weight. The mixture releases heat (exothermic chemical reaction), reaching 110 ºC, and the hardening occurs at room temperature, taking in average of 1 to 2 minutes. The hardened samples were obtained in the form of bars. The starting powders and the mixed powders were characterized by scanning electron microscopy (SEM), dispersive energy spectroscopy (EDS), X-ray diffraction (XRD), and already the hardened samples were submitted to the tests of mechanical resistance to flexure, and characterized in SEM, EDS. The results showed that the addition of alumina to the PMMA influenced the mechanical resistance to flexure with increasing modulus of elasticity, and the capacity of deformation and, finally, the progressive reduction of porosity.