Irregular solution thermodynamics of wood pulp in the superbase ionic liquid [-TBDH][AcO]

Knowledge of solution thermodynamics is fundamental for solution control and solvent selection processes. Herein, experimentally determined thermodynamic quantities for solutions of wood pulp (hardwood dissolving pulp, i.e. cellulose) in [ m -TBDH][AcO] are presented. Model-free activities ( a i,j ) and associated mass fraction ( w i,j ) activity coefficients ( Ω i,j ), are determined to quantify inherent solution non-ideality . Access to the Gibbs energy of mixing, G mix , in combination with associated partial molar thermodynamic quantities, reveal strong enthalpically favourable (exothermic) interactions due to solvent-j and solute-i contact-encounters. Onset of an entropy driven phase instability appears at increased temperatures as excess entropic contributions dominate solvation character of the irregular solutions formed. Thermochemical analysis of cellulose dissolution character in the superbase containing protic ionic liquid [ m -TBDH][AcO] reveals lower critical solution temperature (LCST) behaviour.