Characterization of Amphiphilic Cobaltocenium Copolymers via Size Exclusion Chromatography with Online Laser-Light Scattering and Viscometric Detectors

Abstract

A sample of cobaltocenium copolymer (Copolym) obtained by a controlled polymerization method was characterized by a multi-detector size exclusion chromatography (MD-SEC) method eluted by various pure and mixed mobile phases. The value of number average molecular weight (), estimated by MD-SEC using the above elutes, was comparable with the ones obtained from the SEC standard calibration curve and estimation by the monomer conversion method. The solution properties of the Copolym were studied based on the Mark-Houwink-Kuhn-Sakurada (MH) relationship where the values of the MH exponent of the Copolym in the above solutions were within the values corresponding to a flexible random coil system. The unperturbed end-to-end dimensions of the Copolym were obtained based on the Stockmayer-Fixman extrapolation method. It was found that the degree of flexibility of the Copolym was higher than that of C-C backbone polymers such as atactic polypropylene, and in the range of poly(acrylic acid), which is suggested to be due to the short-range interference effect of the ionic side chains and solvent molecules on the degree of free rotation of the copolymer.