Characterization of Styrene Copolymers Using Size-Exclusion Chromatography with On-line FT-IR Viscometer Detectors

Size-exclusion chromatography (SEC) provides a rapid method for determining molar mass distributions of macromolecules. In this article, we demonstrate the method of SEC coupled with an on-line Fourier-transform infrared (FT-IR) detector and an on-line differential viscometer developed for copolymer characterization. Using a chemometric technique to analyze the FT-IR spectra allows for determining copolymer concentration and composition. The combination of the FT-IR concentration detector and the viscometer allows the universal calibration method to be used for measuring copolymer molar mass. Molar mass distribution and compositional distribution are described and the method's application demonstrated using several types of styrene copolymers.