Síntese e caracterização de poliéster obtido a partir dos produtos naturais curcumina e norbixina

Abstract

Modern life without the presence of polymers is impossible to imagine, since they are used for various purposes, from hospital utensils, household items made from 3d printers and others. In the perspective of finding new polymer materials outside the oil matrix, a viable alternative is to obtain these from natural percussors, the monomers used in the synthesis of natural polymers are important because they present some peculiarities in the polymers formed. This work aims to synthesize and characterize a new polymeric material, a polyester obtained from the natural products curcumin and norbixin, substances extracted respectively from turmeric (long turmeric) and urucum (Bixa Orellana L.) by means of esterification reaction in which can be used as a route of obtaining condensation polymers therefrom among the polyesters. The synthesis was carried out by means of a classical polyester esterification reaction performed under open system under heating and stirring. After reaching a certain temperature, sulfuric acid was added as the catalyst. Keeping the temperature constant after some time, the reaction mixture began to change phase, to present characteristics of foam, but after washing with polar and non-polar solvents became a bright solid. Upon completion of the polymerization, the material was naturally cooled to room temperature becoming a dark amorphous and brittle solid with some brightness. It was carried out the study of its structural and thermal properties through the techniques of characterization: Infrared Spectroscopy with Fourier Transform (FTIR), visible ultraviolet (UV-Vis) spectroscopy, X-ray Diffraction (XRD) X (FRX), Thermogravimetric Analysis (TGA) and Differential Exploration Calorimetry (DSC). The analysis of structural composition of FTIR Spectroscopy showed the appearance of bands of ester carbonyl (1720 cm-1) and reduction of the absorption intensity of O-H stretches, which characterizes a decrease of hydroxyl groups, eliminated in the poly condensation. The thermal characterization curves (TGA and DSC) showed that the synthesized materials showed appreciable phase transitions values for polymeric materials, especially the amorphous polymers with thermoplastic tendencies confirming their great potential as an alternative to polymers of petrochemical derivatives.