A New Stand-Alone Capillary Viscometer Used as a Continuous Size Exclusion Chromatographic Detector

Yau, Wallace W.; Abbott, Scot D.; Smith, G.A.; Keating, M. Y.

doi:10.1021/bk-1987-0352.ch005

Cited by 14 publications

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“…Zur Messung der intrinsischen Viskositat muR also auch an jeder Stelle eines eluierten Peaks die Absolutkonzentration des Polymeren bekannt sein. Die gleiche Schwierigkeit ergibt sich bei der Auswertung der Molmasse aus der absoluten Lichtstreuintensitat Re nach Gleichung (6). In ihr ist K ein Kontrastfaktor, der ne- …”

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Polymeranalytik: Strukturbestimmung von Makromolekülen mit der Gelpermeations‐Chromatographie

Wintermantel

Schmidt

Becker

et al. 1992

Nachr. Chem. Tech. Lab.

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Polymeranalytik: Strukturbestimmung von Makromolekülen mit der Gelpermeations‐Chromatographie

Wintermantel

Schmidt

Becker

et al. 1992

Nachr. Chem. Tech. Lab.

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Size‐Exclusion Chromatography of Polymers

Trathnigg

2000

Encyclopedia of Analytical Chemistry

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Size‐exclusion chromatography (SEC) is a standard technique for determining molar mass averages and molar mass distributions (MMDs) of polymers. Sometimes the termsgel permeation chromatography (GPC) or gel filtration chromatography (GFC) are also used, but SEC should be preferred, because this term describes the mechanism much better: polymer molecules are separated according to their hydrodynamic volumes (which can be correlated with molar mass), with the larger size molecules exiting first followed by the smaller. Molar masses are determined either from a calibration or using molar mass sensitive detectors. In the case of copolymers, the knowledge of chemical composition along the MMD is required, which can be obtained from combinations of different concentration detectors. As the hydrodynamic volumes of different polymers are typically somewhat different, molecules with different chemical composition and different molar mass will be eluted in the same slice of the chromatogram. Obviously, a discrimination between such molecules requires a two‐dimensional separation, in which one dimension may be SEC, and the other one a chromatographic technique, which separates according to chemical composition rather than molar mass, such as liquid adsorption chromatography (LAC), liquid chromatography at the critical point of adsorption (often also called liquid chromatography under critical conditions, LCCC), supercritical fluid chromatography (SFC), temperature rising elution fractionation (TREF), etc. In the lower molar mass range, mass spectroscopy competes with SEC. The most frequently used technique is matrix‐assisted laser desorption/ionization time‐of‐flight mass spectroscopy (MALDI/TOF/MS), which cannot, however, provide quantitatively accurate MMDs. Due to its excellent resolution in molar mass, it can be combined with chromatographic techniques in order to increase the reliability of the analysis.

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Polymer characterization by thermal field flow fractionation with a continuous viscosity detector

Kirkland

Rementer

Yau

1989

J of Applied Polymer Sci

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SynopsisA sensitive flow viscometer detector has been successfully used with time-delay, exponentialdecay thermal field flow fractionation (TDE-TFFF) to produce unique information on polymers. TFFF with a concentration-dependent detector (e.g., refractometer) and a differential capillary viscometer is unable to produce a universal calibration plot that eliminates the necessity of polymer standards for accurate molecular-weight calibration. However, this system directly provides valuable information on the inherent (or intrinsic) viscosity distribution of polymers. Absolute intrinsic viscosity values are measured by TFFF without the need of calibration. Detailed TFFF/inherent-viscosity distribution profiles uniquely describe individual sample differences and are not affected by the experimental conditions used in TFFF separations. These viscosity distributions should be very useful in polymer characterization, since they are closely correlated with polymer end-use and solution properties, as well as to polymer molecule weight.

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A New Stand-Alone Capillary Viscometer Used as a Continuous Size Exclusion Chromatographic Detector

Cited by 14 publications

References 0 publications

Polymeranalytik: Strukturbestimmung von Makromolekülen mit der Gelpermeations‐Chromatographie

Polymeranalytik: Strukturbestimmung von Makromolekülen mit der Gelpermeations‐Chromatographie

Size‐Exclusion Chromatography of Polymers

Polymer characterization by thermal field flow fractionation with a continuous viscosity detector

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