Polymer Characterization by SEC-Viscometry: Molecular Weight (MW), Size (Rg) and Intrinsic Viscosity (IV) Distribution

Abstract

Abstract New polymer characterization capabilities have recently been added to our size exclusion chromatography (SEC) using an on-line viscosity detector. In addition to molecular weight distribution (MWD) capabilities, we now also can determine the intrinsic viscosity distribution (IVD), and the molecular size distribution, i.e., polymer radius-of-gyration, or Rg-distribution (RGD) of polymer samples. Polymer conformation and branching features can now be studied by the log(Rg) versus log(MW) results of a single SEC-viscometry experiment. Also added to our SEC-viscometry analyses is the absolute Mn method recently proposed by J. M. Goldwasser for handling the difficult problems of determining molecular weight (MW) of copolymers and polymer blends. In this new method, the number-average molecular weight (Mn) of a complex polymer sample can be determined by SEC using an on-line viscosity detector, without the need of an on-line concentration detector.