Characterization of the Solvent Properties of Glycerol Using Inverse Gas Chromatography and Solubility Parameters

Abstract

The production of glycerol from the synthesis of biodiesel has led to a market surplus of this polyhydric alcohol and additional research to find new applications for this versatile chemical. This study involves the use of inverse gas chromatography (IGC) to characterize the solute-solvent interactions between glycerol and a homologous series of aliphatic alcohols, in which the latter components are at infinite dilution in the glycerol, which is the stationary phase contained in a packed GC column. The IGC experiments were conducted between 51.5 and 111°C for the n-alcohols ranging from methanol to n-butanol. All of the n-alcohol homologs exhibited positive deviations from Raoult's law as based on mole fraction activity coefficients values ranging from 1.86 to 14.4. The measured mole fraction activity coefficients of the alcoholic solutes in glycerol showed good agreement with literature values, and in some cases with those predicted using existing theoretical models. The mole fraction activity coefficients increased going from methanol to n-butanol, reflecting the change in the alcohol's cohesive energy densities relative to that for glycerol. The total solubility parameter of glycerol calculated from IGC data was found to be 34.8 MPa 1/2 which is in good agreement with that obtained using Hansen solubility parameter approach (31.6 MPa 1/2 ). This data can be used to characterize the solvent properties of glycerol as well as to provide thermodynamic data for the removal of the alcoholic solutes from glycerol.

Separation Performance of BioRenewable Deep Eutectic Solvents

“…For comparison, the same series of solutes was also studied on the pure [Ch]­[Cl] used as the stationary phase. For comparison, we also collected γ i ∞ values for the same series of solutes in the pure glycerol available in the literature. − The experimental values of γ i ∞ have been approximated by the linear regression ln γ ∞ i = a + b / T . The coefficients a and b , as well as the values of γ i (298 K) ∞ calculated with these coefficients, are also given in Tables S1–S3.…”

Inverse gas chromatography study of polyvinylacetate–solvent and polyethylene–solvent systems

“…This division allows analyzing the temperature dependence on this parameter: The entropic term is related to the free volume of the solvent, so is expected to increase with temperature (the free volume of the solvent also increases with temperature, so this compound will be less accessible to polymer lattice); the enthalpic one is expected to decrease with temperature, due to the decreasing of intermolecular forces between polymer and solvent. For this reason, although originally it was assumed a decreasing of Flory Huggins parameter with temperature, in literature it has been described that this parameter can decrease but also increase with temperature.…”

Shear-Assisted Fabrication of Block Copolymer Agglomerates with Various Morphologies in Viscous Medium

“…We replace the acetone with THF, which is a good solvent for both PEG and PS blocks. THF is partially miscible with glycerol and miscible with water . It is reasonable to infer that the liquid threads made from the deformation of the block copolymer solution droplets under a laminar shear flow may not retain their shape with a good solvent for the gelling block.…”

“…THF is partially miscible with glycerol and miscible with water. 41 It is reasonable to infer that the liquid threads made from the deformation of the block copolymer solution droplets under a laminar shear flow may not retain their shape with a good solvent for the gelling block. The block copolymer solution in THF is 20 wt %, and the dispersion medium is a mixture of glycerol and water with the volume ratio of 5:1.…”