| Autor: |
A. Petr, T. Fahr, L. Dunsch |
| Rok vydání: |
1997 |
| Předmět: |
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| Zdroj: |
Berichte der Bunsengesellschaft für physikalische Chemie. 101:1040-1044 |
| ISSN: |
0005-9021 |
| DOI: |
10.1002/bbpc.19971010709 |
| Popis: |
We performed electrochemical reduction investigations of acrylic acid and methylacrylate in aqueous solutions at a mercury cathode. Tetraalkylammonium halides were used as supporting electrolytes and the pH was adjusted in the range of pH = 3-12. Electrolyses in 1 M solutions of acrylic acid have yielded oligomers with a degree of polymerization depending on the pH value. At pH > pK s + 1 the acrylate anion is reduced and forms oligomers, if alkali ions are absent. Polarographic techniques are used to characterize the electrochemical behaviour of the acid and the ester, especially the coupling of two monomeric units, that was found as a radical-substrate coupling reaction for the acrylate anion and an ion-substrate coupling for the ester. The radical species were detected and characterized by electrochemical in situ EPR spectroscopy. The EPR spectrum is attributed to a propagating chain radical of the acrylate anion. In the case of methylacrylate no EPR spectrum could be recorded during the electroreduction. Finally, a reaction scheme for the electrochemical reduction of acrylate anions in aqueous media containing tetraalkylammonium cations is presented. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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