Evaluation of a Commercial Differential Viscometer as a GPC Detector and Its Application to Polymer Characterization

Abstract

When used as a GPC detector, Viscotek's differential viscometer (DV) measures specific viscosities at each elution volume across the chromatogram. With the addition of a concentration detector, intrinsic viscosities may be calculated. As a result, true molecular weights can be calculated via the universal calibration method.

It was found that true molecular weights and branching analysis obtained using DV for acrylate polymers initiated by VAZO and benzoyl peroxide show excellent agreement with those from low angle laser light scattering (LALLS) measurement. Moreover, comparison of intrinsic viscosities for different polymers at the same molecular weights can be made from the DV technique. In general, linear polymers will have a higher IV than branches ones and the concept has been verified for acrylate polymers in this work.

A comparison between DV and LALLS in terms of capabilities, ease of use, and maintenance is also included.