Quantitative structure-property relationships for binary polymer-solvent systems: Correlation weighing of the local invariants of molecular graphs

Correlation coefficients are obtained between the physicochemical values in binary polymer-solvent systems and descriptors calculated from the molecular graphs representing monomers and solvent molecules. These coefficients are examined in connection with the contributions of various local invariants of the graphs, such as the presence of various atoms in the macromolecule and the Morgan vertex degrees of the zeroth, first, second, and third order. The best one-parameter correlation between the Flory-Huggins parameter and the above descriptor calculated for the third-order Morgan degrees has the following statistical characteristics: n = 30, r = 0.9995, s = 0.028, F = 27537 (training set) and n = 30, r = 0.9986, s = 0.053, F = 10294 (test set). For the intrinsic viscosity the best model is based on the first-order connectivity and is characterized by n = 17, r = 0.9555, s = 0.126 cm³/g, F = 157 (training set) and n = 9, r = 0.9608, s = 0.143 cm³/g, F = 84 (test set).