Comparative studies of the chelation of transition metal ions with metal deactivators
| Autor: | Albert W. H. Mau, Jonathan Hodgkin, Hans J. Griesser, Edward Blatt |
|---|---|
| Přispěvatelé: | Blatt, Edward, Hodgkin, Jonathan H, Mau, Albert W-H |
| Rok vydání: | 1989 |
| Předmět: |
Polymers and Plastics
Chemistry Inorganic chemistry chemistry.chemical_element Condensed Matter Physics Copper Catalysis Metal Solvent Metal deactivator chemistry.chemical_compound Mechanics of Materials visual_art Materials Chemistry visual_art.visual_art_medium Dimethylformamide Chelation Equilibrium constant |
| Zdroj: | Polymer Degradation and Stability. 25:19-29 |
| ISSN: | 0141-3910 |
| DOI: | 10.1016/0141-3910(89)90120-1 |
| Popis: | The relative chelating strengths and co-ordination numbers of a series of aromatic-substituted ethanedioic acid bis-hydrazides and N , N ′-di- α -phenoxypropionyl isophthalyl dihydrazide (Cunox AX®) complexed with Cu 2+ , Ni 2+ , Co 2+ and Zn 2+ have been investigated by UV absorption spectroscopy using N , N -dimethylformamide as solvent. The data indicate that there is 1:1 complexation between the cations and the various bishydrazides with equilibrium constants in the range 0·4−4·9 × 10 6 mol −1 , and 2:1 complexation for Cunox with equilibrium constants in the range 0·4−5·2 × 10 11 mol −2 . For two bis-hydrazides, fluorescence quenching experiments were also performed for independent verification of this strong complexation. The complexation data show that these compounds are not only useful as copper inhibitors, but also strongly deactivate other transition metal ions known to accelerate the degradation of polyolefins. A computer simulation of the extent of complexation with increasing ion concentration enabled comparisons to be made between the bis-hydrazides and Cunox. The importance of these results in assessing metal chelators as stabilizers of polyethylene insulated copper cables, and of polyolefins in contact with metals in general, is discussed. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|