Estudo sobre o reaproveitamento do glicerol: produção e aplicação de esteres de glicerol

Abstract

This work studied obtaining triacetate from the glycerol esterification reaction and evaluation the efficiency of different catalysts (sulfuric acid - H2SO4 and heteropolyacid - HPW) with different acetylating agents (acetic acid - AC and acetic anhydride - AN). The esterification of glycerol was carried out under reflux and the glycerol triacetate (TAG) quantified by gas chromatography coupled to mass spectrometer (GC-MS). The HPW and H2SO4 showed good catalytic performance in the esterification of glycerol with AC and AN, wherein the AN acetylating agent favored the production of triacetate. In 1h of reaction, approximately 80% was obtained when the catalysts were used. The products of the reactions with the AN acetylating agent were determined by mass spectrometry with electrospray ionization. For preparation of the wood adhesives, triacetate and H2SO4 were mixed at 80°C for one hour. After this, the tannin was added and the material underwent the curing process. The adhesives A and B were produced with 25 and 40% tannin, respectively. The adhesives were subjected to analysis of CHNS-O, FTIR, thermal analysis (TGA, DTA and DSC), solids and pH determination, rheological study and mechanical analysis. The characterization of the adhesives confirmed their synthesis from triacetate and tannin, their analyzes differed only in solids content and viscosity. Shear strength and rupture percentage values show that the adhesives prepared are very promising and suitable for use.