Studies of the photo-oxidation of polydienes: Part 1—Photo-stabilising effect of some derivatives of diacetyl-monooxime benzoylhydrazone nickel(II) chelates on cis-1,4-polybutadiene

• Published in: Polymer degradation and stability 1987, Vol.18 (2), p.145-155
• Main Authors: Abdel-Bary, E.M., Sarhan, A.A., Abdel-Razik, E.A.
• Format: Article
• Language: English
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/0141-3910(87)90027-9

Three derivatives of diamagnetic diacetyl-monooxime benzoylhydrazone nickel(II) chelates were evaluated as uv stabilisers for cis-1,4-polybutadiene (BR) in solution and in films. In the presence of methylene blue (MB) as singlet oxygen sensitiser, such chelates inhibit the effect of singlet oxygen formed during irradiation by visible light. The photo-stabilising mechanism of the chelates is discussed in terms of their action as singlet oxygen quencher as well as their action as uv absorbers. Further, a stabilising mechanism which involves the trapping of alkyloxy and/or alkylperoxy radicals has also been suggested for two of the chelates. Combination of the most effective chelate and β-carotene as singlet oxygen quencher exhibits synergistic behaviour. The polymer samples which were irradiated in its presence were examined using the Differential Scanning Calorimeter (DSC) technique. The results obtained also demonstrate the photo-stabilising effect of the chelate.