Determination of the solubility parameter of organosolv lignin by inverse gas chromatography

An inverse gas chromatographic (IGC) method has been used to measure the solubility parameters (delta(2)) of organosolv lignin at the absolute temperatures from 333.15 K to 373.15 K. The test probe solvents were n-octane (n-C-8). n-decane (n-C-10). n-dodecane (n-C-12), and n-tetradecane (n-C-14). The specific retention volumes of the solvents (V-g(0)), the molar enthalpy of sorption (Delta H-1(s)), the partial molar enthalpy of mixing at infinite dilution (Delta H-1(infinity)), the molar enthalpy of vaporization (Delta H-v), the activity coefficients at infinite dilution (Omega(infinity)(1)), and Flory-Huggins inter action parameters (chi(infinity)(12)) between organosolv lignin and probe solvents were obtained. The results showed that the above four probes are poor solvents for organosolv lignin; at the same temperature, the chi(infinity)(12) reduced with the increase of the carbon number of probe solvents. The average solubility parameter of organosolv lignin was determined as 19.03 (J center dot cm (-3)) (1/2).