Solubilities of R32, R245fa, R227ea and R236fa in a phosphonium-based ionic liquid

New solubility data for difluoromethane (R32), 1,1,1,3,3-pentafluoropropane (R245fa), 1,1,2,2,3,3,3-heptafluoropropane (R227ea) and 1,1,1,3,3,3-hexafluoropropane (R236fa) in trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate ([P14666][TMPP]) at temperatures from 292 K to 344 K and at pressures from 0.01 MPa to 1.07 MPa is presented in this work. Low temperature and high pressure can improve the solubilities of hydrofluorocarbons in [P14666][TMPP]. Hydrofluorocarbons are more soluble in [P14666][TMPP] than their corresponding alkanes. Dispersive force, dipole-dipole interaction and hydrogen bond interaction were considered to exist between HFC and [P14666][TMPP]. A modified Krichevsky-Kasarnovsky equation was used to correlate the solubilities of R32, R227ea, R236fa and R245fa in [P14666][TMPP] with the mean absolute relative deviations and the maximum absolute relative deviations less than 2.0% and 4.3%, respectively.