Síntese e caracterização de poliamida a partir do produto natural norbixina e o fármaco dapsona

Abstract

The polymeric materials are essential for the maintenance of the quality of life. Among these, the polyamides stand out as polymers of great economic importance with a wide range of applications, such as textile fibers, automotive parts, electronic components and several others. In this context, this work aimed to synthesize and characterize a new polymer, the poly (4-sulfonylbisbenzene norbixinamide) or PA 12.24, obtained from the natural product norbixin and the drug dapsone. The synthesis, carried out by means of a reaction of poly condensation between a dicarboxylic acid and a diamine, was performed in system under heating and stirring. After 1 hour at 170 ° C, cobalt acetate was added as the catalyst. After the polymerization was complete, the material was naturally cooled to room temperature, in which, it became stiff and brittle. The structural properties, thermal and morphological characteristics of the material through the characterization techniques: Spectroscopy in the Ultraviolet and Visible region (UV-Vis), Spectroscopy of infrared with Fourier Transform (FTIR), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and Differential Exploratory Calorimetry (DSC). At structural composition analyzes of FTIR Spectroscopy presented the appearance of typical bands of amide carbonyl (1595 cm-1) it is the disappearance of the strong band characteristic of the C-O bond, justified by norbixin carboxylic functional groups, eliminated in the reaction of poly condensation. The UV-Vis Spectroscopy evidenced a process of discoloration of the polyamide compared to norbixin, as well as an increase in concentration of the C = O chromophore groups of polymers by virtue of the polymerization reaction. The curves of TGA and DSC showed phase transitions related to melt temperature (Tm = 502°C) and glass transition (Tg = 407°C), which, together with the XRD analysis, confirmed the semi-crystalline character of PA 12, 24. According to the results obtained, the formation of the new polyamide, with well-defined characteristics and distinct of its precursor monomers, was confirmed, ensuring the consistency and reproducibility of the synthesis method. The results of this study also represent a starting point for the evaluation of the interest and feasibility of using the new polyamide in the production of automotive parts, electronic components and in the synthesis of membranes with application in the field of medicine, thus confirming potential as an alternative to petrochemical derivative polymers.