Rotas enzimáticas e sintéticas para epoxidação do óleo de mamona

Abstract

The work addresses the synthetic and enzymatic epoxidation of castor oil using different catalysts, analyzing their conversion rates, epoxidation and selectivity using 1H NMR, as well as chemical analysis using FTIR. The thermal behavior of the resulting degradations and the gases released during pyrolysis through TGA-IR/DTG are also discussed, in addition to the thermal degradation kinetics calculated by the Friedman, FWO and Vyazovkin models. The results show a synthesis time of six hours, more suitable for epoxidation without AI, and a conversion rate of 50% using organic solvent. Furthermore, changes in the structure of unsaturated and hydroxyl bonds are identified during reactions, indicating epoxidation and dehydration in enzymatic reactions. Thermogravimetric analyzes revealed the destabilization temperatures of enzymatic and synthetic epoxidations (>350ºC). The thermal degradation kinetics showed the interference of dehydration events in the degradation activation energies, indicating the models used as the best kinetic models to calculate the activation energies of castor oil epoxy degradation. In summary, the study highlights the importance of catalysts, solvents and reaction time in epoxidation and thermal degradation, indicating that enzymatic epoxidation is effective in replacing synthetic reactions, becoming a new alternative route, to promote a more sustainable and economically process viable.