Solid-liquid Solubility of Dehydroabietic Acid and Its Reaction Crystallization Coupled Single Separation Method
The laser monitoring technique was used to determine the equilibrium end point.The solid-liquid solubility of dehydroabietic acid at 282-325 K in methanol,absolute ethanol,n-propanol and n-butanol was determined by dynamic method.The λh model,Wilson model and simplified model were used to correlate the solubility data.Dehydroabietic acid was isolated by supercritical/subcritical CO2-enhanced amination reaction-crystallization coupling method.The purity of dehydroabietic acid was detected by gas chromatography(GC)analysis,melting point and optical rotation rate.The results showed that the solubility of dehydroabietic acid in four alcohol solvents increased with the increase of temperature,and the order of the solubility in different solvents was as follows:n-butanol＞n-propanol＞absolute ethanol＞methanol.The maximum average relative error values of the solubility data of dehydroabietic acid in four alcohol solvents correlated by λh model,Wilson model and simplified model were 1.23％,2.15％and 0.87％,respectively.Through orthogonal experiment,the optimal reaction conditions of supercritical/subcritical CO2 amination reaction-crystallization coupling single-separation dehydroabietic acid were obtained as follows:reaction time of 50 min,reaction temperature of 308 K,CO2 pressure of 7.5 MPa,solvent ethanol volume fraction of 50％,stirring speed of 400 r/min.The yield of dehydroabietic acid was 81.85％and the purity was 99.62％.The melting point of dehydroabietic acid was 446.0-446.5 K,and the optical rotation[α ]20D was+62.2°.
万方数据
维普
