Zur ermittlung der struktur und unverträglichkeit von pfropfcopolymeren durch messungen der lichtstreuung und phasentrennung in lösung

From theoretical considerations it is concluded that molecular weights and radii of gyration of the grafted chains in graft copolymers as well as the incompatibility of the grafted chains with the backbone polymer can be determined by light-scattering measurements in solution if the solvent used for these measurements is isorefractive with respect to the backbone polymer and if the weight fraction of the grafted chains is known. The new method for determining the incompatibility from anomalous Zimm-Diagrams is illustrated for mixtures of polystyrene and a chemically homogeneous ethylene/vinyl acetate random copolymer and is applied to fractions of the corresponding graft copolymers. The results of the light scattering measurements are compared with phase separation data from turbidimetric measurements.