Inverse gas chromatography (IGC) has been widely used to determine the Flory-Huggins parameters, X, between solutes (probes) and polymers. This study correlated the Flory-Huggins parameter data using a multiparameter model, which included dispersion, polarity, acidity, and basicity components. The parameters of poly(E-caprolactone) (PCL) and polyepichlorohydrin (PECH) were calculated from IGC data using a series of probes. The parameters of the polymers were used to evaluate mutual miscibility between PCL and PECH. The results predicted miscibility in agreement with the conclusion of an IGC study using blends of PCL and PECH. A method to estimate the confidence interval of polymer parameters was proposed. The anomalous solubility parameter of polymer mixtures previously reported was also explained using this model. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 4085-4091, 2009