Study of solubility of mannitol in different organic solvents.

Abstract

Biomass plays a significant role in the renewable energy sector, and sorbitol and mannitol are associated with biomass through their production, use as carbon sources, and modification of biomass-based materials. They can be produced from biomass sources such as corn, wheat, and other plant materials. They can also serve as carbon sources for microorganisms involved in biomass conversion or be used to modify the properties of biomass-based materials. Both sorbitol and mannitol, as sugar alcohols, have distinct properties and applications. Sorbitol is highly hygroscopic and more soluble in water, while mannitol, a crystalline solid produced by the hydrogenation of fructose, is non-hygroscopic and less soluble. Through the solubility experiments conducted in this study, the information from the literature has been corroborated, showing that mannitol, despite being an isomer of sorbitol, has lower solubility ranges. It is also demonstrated that mannitol's solubility progressively increases in all solvents as the temperature rises. The solubility range obtained is 10-4, except for water, which has a range of 10-2. This significant difference in solubility is due to water's ability to form hydrogen bonds with mannitol. As corroborated by the literature, water is the solvent with the Hildebrand parameter closest to that of mannitol. The range of enthalpies obtained is 28-41 kJ/mol, with a slight deviation from the expected values for MIBK and dioxane.Regarding the polymorphs of sorbitol, analyzing the commercial sample and all samples from the experiments, it is concluded that mannitol remains in its most stable polymorph, beta. Overall, the mass ratio solubility decreases at the higher temperature (340K) in order: H2O > MeOH > EtOH > TBA > 1-Prop > 2-Prop > ButOH > 2-ButOH > MIBK > Dioxane > Butanone > Acetone. Simultaneously, the solubility results have been more favorable for water, followed by polar protic solvents.