Analysis Gel permeation chromatography

The polydispersity is the most common measure of the breadth of the molecular weight distribution because it is easily obtained from gel permeation chromatography analysis, and because, as will be shown later, it is a normalized measure of breadth of distribution (unlike variance). 

Swab samples showed approximately 16% loss in screen factor from the wellhead and 15% loss in viscosity (Table 4). Polymer and tracer concentration measurements and, gel permeation chromatography analysis showed that the loss in properties was due to degradation of the polymer and not to dilution. 

This effect is very important during the preparation of the nanocomposite via melt blending, as observed by Gilman et al. for a PS nanocomposite, where gel permeation chromatography analysis of the samples, extruded without a nitrogen flow in the extruder, showed some evidence of degradation in the form of lower molecular weight. ... 

---