Inverse gas chromatographic studies have been carried out for 1,2,3-propanetriyl trinitrate and 1,2,4-butanetriyl trinitrate in molten α,ω-dihydroxy poly(tetramethylene carbonate) (7) and α,ω-dihydroxy polyoxyethylene (9). Thermodynamic sorption and mixing functions and the Flory-Huggins interaction parameter were derived for 1,2,3-propanetriyl trinitrate. The results are compared to those obtained using 1,2,3-propanetriyl triacetate as solute in the same polymers. All solutes are more compatible with 9 than with 7, as shown by the higher values of specific retention volumes and partial molar enthalpy of sorption. The partial molar enthalpies of mixing of 1,2,3-propanetriyl trinitrate with 7 and 9 are markedly higher than those of 1,2,3-propanetriyl triacetate. This unfavourable effect on compatibility is compensated by higher partial molar entropies of mixing in the case of the nitrate, which leads to comparable behaviour for both solutes.