Determination of free carbonyl and unbound water in polyacrolein by infrared spectrometry
| Autor: | J. W. Forbes, D. O. Schissler |
|---|---|
| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Journal of Polymer Science Part C: Polymer Symposia. 8:61-70 |
| ISSN: | 1935-3065 0449-2994 |
| DOI: | 10.1002/polc.5070080107 |
| Popis: | The determinations of free carbonyl and unbound water contents of polyacrolein samples by standard chemical methods are not feasible because of labile hydration-dehydration equilibria. The conditions used in the chemical determinations of carbonyl and water lead to quantitative dehydration and therefore always yield values of total carbonyl and total water content. An infrared method for the determination of free carbonyl and unbound water has been developed in which these labile equilibria are not perturbed. Polyacrolein, an insoluble and infusible substance, required the development, of a quantitative spectroscopic technique applicable to powdered solid samples. KBr pressed plate techniques are not applicable because they introduce the serious problem of water contamination inherent with the KBr methods. Free carbonyl and unbound water in polyacrolein have characteristic infrared absorption bands. The absorptivities of these bands were determined by appropriate standards. The method developed consists of spectroscopic examination of sample-Fluorolube emulsions in fixed path infrared cells. The free carbonyl and the unbound water contents are then calculated as if the emulsion were a true solution of known concentration. The absorption due to the water bending mode at ∼6.1 μ is used for the calculation of the free water content, and the absorption due to the C=O stretching mode at ∼5.83 μ is used as a measure of the free carbonyl. An alternate method of analysis was developed after determining an absorptivity for the CH2 bending mode in polyacrolein and using this band as an internal reference. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|