Universal calibration of gel permeation chromatography using evaporative light scattering detector coupled with viscometer

Abstract

The linearized evaporative light scattering detector (ELSD) allows the evaluation of molecular weight distributions (MWD) of a range of polymers using conventional gel permeation chromatography (GPC), and is a suitable replacement for the differential refractive index (DRI) detector in applications which will benefit from fast equilibration, solvent gradients or when working with low polymer concentrations. Further, when DRI is coupled with a viscometer, the Universal Calibration GPC method also allows the evaluation of Mark–Houwink–Sakurada parameters K and alpha, which provides valuable information on the chemical structure of polymer chains. Therefore, for a wider acceptance of ELSD in GPC, we investigated the possibility of coupling the ELSD with the viscometer. Recommendations are provided for successfully coupling the ELSD and viscometer, as well as on software adjustments to calculate K and alpha parameters. For linear polyethylene, a good correlation was found between the measured and the expected K and alpha values.