Calibration Methods for Field-Flow Fractionation Using Broad Standards. I. Thermal Field-Flow Fractionation

Publisher Website
Google Scholar
Abstract
Thermal field-flow fractionation (ThFFF) is used for the determination of molecular weight (MW) distributions of synthetic polymers. This is usually achieved utilizing a series of narrow MW polymer standards. A major drawback in this approach is the very limited number of polymers which have such standards available. This paper reports a method of calibration which utilizes one or more broad standards for which the average MW values are known. It was observed that 1) the use of number-average MW data tends to produce large variation in calibration constants and hence the MW generated, 2) the use of two polydisperse standards and their weight-average MW (M w) provides reasonable calibration in comparison with the conventional method using narrow MW standards, and 3) even better calibration is obtained using multiple broad standards and their M w values. The new method should expand the applicability of ThFFF to include a wider range of polymer types.