Polymer–polymer interaction parameters for homopolymers and copolymers from light scattering and phase separation experiments in a common solvent

摘要: The thermodynamic behavior of the quaternary system DMAc/PS/PAN/SAN and all its solvent containing subsystems [DMAc: dimethylacetamide, PS: polystyrene, PAN: polyacrylonitrile, SAN: P(S–ran–AN)] was studied in terms second virial coefficients phase separation range moderate polymer concentrations. most remarkable finding consists fundamental discrepancies between Flory–Huggins parameters obtained for interaction segments X Y either straightforwardly from light scattering experiments (ranging −0.88 to −0.14) that resulting modeling measured diagrams (+0.01 +0.33) or solubility parameter theory (+0.03 +1.92). reasons disagreement even sign are discussed A2XY, osmotic referring opening intermolecular contacts by insertion W2, normalized excess Gibbs energy...