A kinetic study on autoxidation of α-naphthol-formaldehyde polymer in aqueous alkaline solutions
| Autor: | Mohammad Kameli, Khodadad Nazari, N. Esmaeili, B. Mohajerani |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Journal of Polymer Research. 14:157-165 |
| ISSN: | 1572-8935 1022-9760 |
| DOI: | 10.1007/s10965-006-9096-0 |
| Popis: | α-naphthol-formaldehyde polymer having active methylene groups and low average molecular weight of 1,000–2,000 was synthesized and characterized by FT-IR and gel permeation chromatography(GPC). Macroscopic kinetics of autoxidation of the polymer was investigated in an aqueous alkaline solution using UV/Vis spectrophotometry. Autoxidation processes in the presence of oxygen (or air) and hydrogen peroxide were associated with a color change of the solution to blue, which was monitored at 650 nm. The overall reaction rate law, order of the reaction, kinetic rate constants, and a proposed mechanism for the autoxidation reaction were obtained and reported. Infrared spectrophotometry shows that autoxidation takes place via conversion of methylene groups into carbonyls. Furthermore, kinetic data confirms the proposed mechanism for this autoxidation reaction which is of pseudo zero-order with respect to the polymer and first-order to the oxidant. The obtained kinetic rate constants of the autoxidation reaction by air and hydrogen peroxide are 0.0052 ± 7.1 × 10−4 min−1 and 0.0044 ± 9.7 × 10−4 min−1 at 25°C, respectively. |
| Databáze: | OpenAIRE |
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