Controlled Rate Thermal Analysis (CRTA) as a Fast and Effective Method for the Development of Ceramic Powders of Synthetic Hydroxyapatite at Low Temperatures

Abstract

One of the main limitations for applying synthetic hydroxyapatite as a filler in cement and other formulations in orthopedic surgery is its morphology. The present work shows the obtaining of synthetic hydroxyapatite powders at low temperatures such as 300 and 850ºC using the Controlled Rate Thermal Analysis (CRTA) technique. The powders obtained were characterized by IR spectroscopy and X-ray diffraction, showing that the phase formed corresponds to crystalline hydroxyapatite. The specific surface area values determined are between 17 and 66 m2/g with a pore size between 50-300 Å. The transformation of phases in the synthetic hydroxyapatite is studied by Dynamic Thermogravimetric Analysis and CRTA techniques, allowing the kinetic calculations of the transformation using two methods of data processing, determining the activation energy (Ea), pre-exponential factor (A), and model kinetic most likely in each stage. The results show the effectiveness and usefulness of the CRTA technique for preparing synthetic hydroxyapatite powders with different specific surface areas, which makes this technique attractive for medical purposes.