Study of the effect of natural antioxidants in polyethylene: Performance of β-carotene
| Autor: | Luca Major, Dóra Tátraaljai, Béla Pukánszky, Enikő Földes |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
chemistry.chemical_classification
Antioxidant Materials science Polymers and Plastics medicine.medical_treatment Induction period Carotene Active packaging Polymer Polyethylene Condensed Matter Physics Branching (polymer chemistry) Photochemistry chemistry.chemical_compound chemistry Mechanics of Materials Phosphonite Materials Chemistry medicine Organic chemistry |
| Zdroj: | Polymer Degradation and Stability. 102:33-40 |
| ISSN: | 0141-3910 |
| DOI: | 10.1016/j.polymdegradstab.2014.02.012 |
| Popis: | The effect of β-carotene on the behaviour of polyethylene stabilised with α-tocopherol and a phosphonite antioxidant was studied under processing and storage conditions. The amount of β-carotene ranged between 0 and 2000 ppm. The polymer was characterised by different methods after processing then during and after storage at ambient temperature in light and dark. β-Carotene hinders the oxidation of polyethylene and does not increase the chain extension reactions during processing, though more vinyl groups and phosphonite molecules react. β-Carotene colours polyethylene strongly already at low concentrations. The reactions of the polymer and β-carotene are affected strongly by the storage conditions. The presence of β-carotene does not influence the stabilising efficiency of the primary and secondary antioxidants. In dark the molecular structure of the polymer does not change appreciably, while the reactions of β-carotene lead to an increase in the yellowness index. In light the molecular characteristics of polyethylene undergo significant changes indicating long chain branching. The polymer fades rapidly after an induction period. The length of the induction period is not influenced by light. The rate of the degradation reactions of β-carotene during storage is controlled by its concentration and film thickness. Visible autoaccelerated decomposition in light renders β-carotene candidate as an indicator in active packaging materials. |
| Databáze: | OpenAIRE |
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