POLY 150 |
| Size exclusion chromatography (SEC), is a well-established technique for determining the molecular weight distribution of polymers on the basis of size in solution. Typically, during the analysis, molecular sizes are converted into molecular weights by use of a calibration curve, established for a series of well-defined polymers of known molecular weight. However, in many situations, this method is unsatisfactory as the results obtained are very dependent on the chemistry of the samples under investigation, and the number and type of polymer standards is quite limited. To counter this problem, new methodologies have been developed utilizing detectors that respond directly to molecular properties and remove the dependence on sample chemistry. One such detector is the flow viscometer, which responds to the intrinsic viscosity of polymers and gives molecular weight via the so-called universal calibration technique. Unfortunately, the drawback of traditional designs of viscometers is the large effective cell volume and resulting excessive system dispersion. This high dead volume leads to peak broadening that can strongly influence the accuracy of calculated results. Also, most commercial viscometers are not suited to low flow rates and applications where sample size is limited. To counter these issues, a new miniaturized chip-based viscometer has been designed for polymer analysis. The chip-based system has a much-reduced, effective cell volume compared to traditional detectors and is capable of operating at extremely low flow rates. Using the new detector leads to a significant reduction in system dispersion, giving more accurate peak shapes and a significant improvement in the accuracy of results. This poster introduces the chip-based viscometer and illustrates the application of the device in polymer analysis. |
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General Papers: Synthesis and Characterization
6:00 PM-8:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Division of Polymer Chemistry |