The partial molar enthalpies of mixing at infinite dilution Delta H-1(infinity) of a series of 23 solvents (1), covering a fairly broad range of polarity, with liquid poly(ethylene oxide) and poly(tetramethylene oxide) (2) have been measured by gas-liquid chromatography over the range 70-140 degrees C. The variations of Delta H-1(infinity) have been analysed in terms of probe structure through linear multiparametric correlations involving the molar volume V (or molecular refraction MR), the lowest unoccupied molecular orbital (LUMO) energy epsilon(L) and the hydrogen-bond donating power alpha (Taft scale) as probe polarity descriptors. Statistically significant correlations are obtained, emphasizing that an exothermic mixing process arises essentially from negative contributions of the epsilon(L) and alpha terms : the ether function of the chain behaves as an n-donor and as a hydrogen-bond acceptor. The positive contribution of the MR term is a direct measure of the cavitation effects : for the two polyethers, and polystyrene, poly(vinyl acetate) and poly(vinylidene fluoride) previously studied, the corresponding coefficients of the MR term are an increasing linear function of the cohesive energy density of the polymers as measured by the square of their Hildebrand solubility parameters delta(2).