The characterization of polyelectrolytes is demonstrated by combination of different ultracentrifuge methods with laboratory as well as technical poly(dially1 dimethyl ammonium chloride) samples. Low speed sedimentation equilibrium in an analytical ultracentrifuge was used to determine the molecular weight averages M, and M,. The method was shown to be applicable even in case of partly aggregated solutions and the amount of aggregates was established. Equilibrium sedimentation in a density gradient of a preparative ultracentrifuge allows to separate linear and branched parts. While structural uniform polymers are distributed in a Gaussian band, nonuniformities lead to deformations of distribution curves. With mathematical curve analysis structural portions can be determined.
Charakterisierung des kationischen Polyelektrolyten Poly(dially1-dimethyl-ammoniumchlorid) mit Ultrazentrifugenmethoden
Die Charakterisierung von Polyelektrolyten durch Kombination verschiedener Ultrazentrifugenmethoden wird am Beispiel von Poly(dially1-dimethyl-ammoniumch1orid)-Proben aus Labor-und technischen Synthesen dargestellt. Unter Anwendung des ,,low speed" Sedimentationsgleichgewichts in der analytischen Ultrazentrifuge werden die Molekulargewichtsmittelwerte M , und M, bestimmt. Es wird gezeigt,