Avaliação da resistência térmica de surfactantes à base de sais de ácidos aminobenzóicos

Abstract

The widespread spread of nanotechnology in current times requires more and more studies to understand the evolution of nanotechnological materials. Obtaining good properties in polymer / clay nanocomposites mean that more in-depth studies are needed. performed on the thermal stability of surfactants at processing temperatures of these materials. Organically modified bentonites with quaternary ammonium salts have enormous potential industrial. Organophilized bentonites find higher technological and economic application in the plastics industry, where they are used as additives for mechanical reinforcement and thermal. In this work, four aminobenzoic acids were converted to primary ammonium salts and thereafter the thermal stability of these four primary ammonium salts, such as salts of 3,4-diaminobenzoic, 4-amino-2-hydroxybenzoic, 3,5-diaminobenzoic and 5-amino-2- acids hydroxybenzoic acid was evaluated, aiming at its subsequent intercalation in bentonite clays, with the purpose of making them organophilic for use in polymeric nanocomposites. The salts were thermally characterized by thermogravimetry under air. The results indicated than the salts of 3,5-diaminobenzoic acids, 4-amino-2-hydroxybenzoic and 5-amino-2- hydroxybenzoic acid degraded at approximately similar temperatures (153 o C, 153 o C and 164 o C respectively) and the 3,4-diaminobenzoic acid salt was degraded at higher, approximately 216 o C. In addition, this study suggests that the salt of 3,4- diaminobenzoic acid is likely to be successful in its use as a surfactant for use in nanocomposites.