Síntese e polimerização de naftoxazinas contendo grupos furano: uma estratégia para a obtenção de novos termofixos oriundos de fontes renováveis

Abstract

Naphthoxazines are a class of compounds with potential application in obtaining high performance polymeric materials. Such application of these compounds, however, is still scarcely explored in the literature. Combined with the search for new high-performance materials, the development of bio-based polymers has gained a lot of attention. In this sense, the inclusion of furan groups in polymers has been explored as a strategy that combines the search for high performance materials with the search for the development of bio-based materials. In this work, novel naphthoxazines monomers containing furan groups were synthetized. The syntheses were carried out in a single step, without the use of solvents and catalysts, obtaining the products in satisfactory yields and high purity. The naphthoxazines had their chemical structures completely characterized by FT-IR, 1H-NMR and 13C-NMR techniques. The thermal analysis (DSC and TGA) showed that all naphthoxazines exhibit exothermic typical polymerization events, making these compounds suitable for obtention of poly(naphthoxazines) resins, but suffer significant mass losses at temperatures below the onset polymerization temperature. In this way, a catalyst (1 mol% MgCl2) was used in order to allow the polymerization of the compounds before the mass loss events. The FT-IR analysis showed strong evidences of the formation of poly(naphthoxazines) and TGA analyses showed that the resins has high thermal stability, with high flame resistance and self-extinguishing properties (LOI >28), which makes these compounds attractive in the development of bio-based and high-performance materials.