column. This lack of separation at the higher molar mass end of the chromatogram
results in incorrect molar mass average and long chain branching (LCB)
calculations, as is depicted in the plot of the radius of gyration (R g ) or the intrinsic
viscosity ([η]) versus molar mass (M ) (Fig. 4.6). The separation and
Fig. 4.4 Flow scheme of the AF4 focusing step (reprinted from [29] with permission of Elsevier
Limited)
Fig. 4.5 Elution curves and molar mass plots of LDPE and HDPE samples; (a) separation by
HT-AF4 and (b) separation by HT-SEC (reprinted from [6] with permission of Elsevier Limited)
4.2 Application of Field-Flow Fractionation to Polyolefins
153