Orientador(es)
Resumo(s)
The solubility of the trans isomers of cinnamic acid, p-coumaric acid and ferulic acid was measured in water and seven organic solvents (methanol, ethanol, 1-propanol, 2-propanol, 2-butanone, ethyl acetate and acetonitrile), at 298.2 K and 313.2 K, using the analytical shake-flask technique. The melting temperatures and enthalpies of the solutes were studied by differential scanning calorimetry, while solute solid structures were identified by powder and single X-ray diffraction. The NRTL-SAC model was applied to calculate the solubility of trans-cinnamic acid and trans-ferulic acid in pure solvents. For trans-p-coumaric acid, the NRTL-SAC was combined with the Reference Solvent Approach, as the solute melting properties could not be determined. The global average relative deviations (ARD) were 32% and 41%, in the correlation and prediction stages, respectively. The Abraham solvation model was also applied. The global ARD were 20% for correlation and 29% for predictions, which can be considered very satisfactory results for these semi-predictive models.
Descrição
Palavras-chave
Abraham solvation model Cinnamic acid derivatives NRTL-SAC model Solid phase studies Solubility
Contexto Educativo
Citação
Vilas-Boas, Sérgio M.; Alves, Rebeca S.; Brandão, Paula; Campos, Leila M.A.; Coutinho, João A.P.; Pinho, Simão P.; Ferreira, Olga (2020). Solid-liquid phase equilibrium of trans-cinnamic acid, p-coumaric acid and ferulic acid in water and organic solvents: Experimental and modelling studies. Fluid Phase Equilibria. ISSN 0378-3812. 521, p. 1-10