Spectroscopic studies of carbon. XX. The pyrolysis of polyvinylidene chloride and of Saran
| Autor: | M.J.D. Low, M.L. O'shea, C. Morterra |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Materials science
Carbonization Analytical chemistry Infrared spectroscopy chemistry.chemical_element Condensed Matter Physics Polyvinylidene fluoride chemistry.chemical_compound Polyvinyl chloride Monomer chemistry Polymer chemistry Chlorine General Materials Science Polyvinylidene chloride Pyrolysis |
| Zdroj: | Materials Chemistry and Physics. 27:155-179 |
| ISSN: | 0254-0584 |
| DOI: | 10.1016/0254-0584(91)90114-a |
| Popis: | Fourier transform photothermal beam deflection spectroscopy was used to record the spectra of chars produced by heating in vacuo pure polyvinylidene chloride (PVDC) and the copolymer Saran over the 100–690°C range. The infrared spectra obtained provide direct information about the degradation and subsequent carbonization of PVDC and Saran. Pyrolysis of both homopolymer and copolymer at T = 200°C results in the destruction of the original ordered vinylidene structure and there is spectroscopic evidence for the formation of polyenic sequences. At T>200°C the spectra show the development of an increasingly aromatic system with rings containing evidence of chlorine substitution. As pure polyvinylidene chars contain 50% less hydrogen than their polyvinyl counterparts, the spectra of chars obtained at T>400°C show little vibrational structure in the region >2000 cm−1, and at degradation temperatures >500°C no vibrational features are observable over the entire 4000 - 500 cm−1 range. In contrast, the inclusion of only a small percentage of vinyl monomer in the copolymer Saran results in chars whose spectra exhibit vibrational features up to degradation temperatures of 690°C. The spectroscopic character of PVDC and Saran chars and their oxidation are discussed in detail. In addition, these results are compared and contrasted with earlier analyses of the chars of polyvinyl chloride and polyvinylidene fluoride. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|