Resina benzoxazinas e compósitos preparados a partir de fenóis provenientes de fontes renováveis

Abstract

Benzoxazine resins belong to a class of phenolic resins that has shown growing interest in the field of thermosets for application in high-performance materials. They have excellent thermal and mechanical properties, ease of synthesis and, above all, flexibility in molecular design, which allows adapting or requiring specific properties. Much attention from academia and industry has been given to synthetic benzoxazines based on natural origin compounds, such as, cardanol, derived from the cashew industry, and piceid, from solid waste from the wine industry. Furthermore, the influence of the addition of PAni doped with cardanol (PC) as filler on the properties of benzoxazine resins was investigated. The polymeric materials were characterized by FTIR, TEM, TGA, DSC, electrochemical impedance spectroscopy and optical microscopy. From the results, it was found that cardanol and piceid were efficient as phenolic components for the preparation of benzoxazine resins, and that the benzoxazine resin prepared with furfurylamine presents greater thermal stability and lower corrosion rate when compared to ethylenediamine. The composites have temperatures typical of thermal curing by oxazine ring opening and the addition of 3% m/m promotes a reduction in the maximum curing temperature compared to the composite prepared with 1% PC. The composites result in corrosion are inferior to those found for pure resin. When the composites are compared with each other, the Bz-C/PC-1% is the one that presented the best anticorrosive results.