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On-line measurement of the RMS radius of gyration and molecular weight of polyimide precursor fractions eluting from a size-exclusion chromatograph |
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| Authors: | Seong Kim Patricia M Cotts Willi Volksen |
| Abstract: | The recent introduction of multiangle light-scattering detectors for size-exclusion chromatography has made possible the measurement of the root mean square radius of gyration (Rg) and molecular weight (M) of polymer fractions eluting from a size-exclusion chromatography column. The characterization of the dimensions of a polymer may be accomplished with only a few milligrams. The dimensions of a polyimide precursor prepared by the condensation of the meta-diethyl ester of pyromellitic dianhydride with para-phenylene diamine have been measured with this technique. The dependence of Rg on M across the distribution is compared with that predicted for a freely rotating chain, and with other similar polymers measured with hydrodynamic techniques. |
| Keywords: | polyimide precursor fractions on-line size exclusion chromatography of molecular weight and radius of gyration from on-line SEC of polyimide precursors chromatographys of polyimide precursor fractions with on-line light scattering detector light scattering detection on-line in SEC measurements |