SÍNTESIS Y CARACTERIZACIÓN DE MATERIALES HÍBRIDOS A BASE DE POLIURETANO PARA SU POTENCIAL APLICACIÓN COMO SUSTITUTO DE TEJIDO ÓSEO

Abstract

This work focuses on the study of organic-inorganic hybrid materials based on siloxane and polyurethane modified with calcium nitrate (Ca(NO3)2 4H2O) and triethyl phosphate (C2H5O)3PO) synthesized by the sol-gel method. The organic component of hybrid materials was developed in two steps. The first step was the synthesis of polyester using polyetilenglycol, succinic acid and etilen glycol as raw materials. The second step was the synthesis of polyurethane using the polyester synthesized previously as the soft segment, hexamethylene diisocyanate as the hard segment and (3-aminopropyl)triethoxysilane as chain extender. The inorganic component of hybrid materials was tetraethyl orthosilicate. Calcium and phosphorus were added by using calcium nitrate and triethyl phosphate, respectively. The ratios (by weight) employed were 0% and 5% of calcium percent and 0%, 1%, 3%, 5% of triethyl phosphate. In vitro bioactivity of the hybrid materials is expected to be enhanced by adding calcium and phosphate. The characterization of materials was carried out by Fourier-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Hybrid´s bioactivity was evaluated using simulated body fluid (SBF). Polymers and hybrids degradability was evaluated using buffer phosphate solution (BPS). The bioactivity results of hybrid materials show that the organic component has a significant influence due to it forms acidic groups on solution which decreases the pH of SBF solution that favors the calcite precipitation therefore hydroxiapatite precipitation was inhibited.