Natural extracts as potential source of antioxidants to stabilize polyolefins

• Type: Article in International Scientific Journal
• Date: 2011

Authors

M. S. Dopico-García (Author) Other; M. M. Castro-López (Author) Other; J. M. López-Vilariño (Author) Other; M. V. González-Rodríguez (Author) Other; P.Valentão (Author) FFUP; P. B. Andrade (Author) FFUP; S. García-Garaba (Author) Other; M. J. Abad (Author) Other

Journal

Title: Journal of Applied Polymer Science

Vol. 119 No. 6

Pages: 3553-3559

ISSN: 0021-8995

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 28 Citations

Scopus - 37 Citations

Scientific classification

FOS: Medical and Health sciences > Other medical sciences

CORDIS: Health sciences

Other information

Authenticus ID: P-002-T8T

Resumo (PT): Several natural matrices were investigated as potential sources of antioxidants to be used as plastic additives. Extracts of four matrices obtained under the same experimental conditions were initially considered: green tea, black tea, Lippia citriodora and Hypericum androsaemum. Both, the antioxidant activity of the extracts and their content in flavanols and quercetin, were compared. The antioxidant activity was determined by DPPH analysis and the phenolic composition by high performance liquid chromatography (HPLC) using ultraviolet (UV) diode array and fluorescence (FL) detectors. Concentration of the flavanols reduced in the same way as their antioxidant activity starting with green tea, through black tea, Hypericum androsaemum, and Lippia citriodora. The performance of polypropylene samples stabilized with green tea extract, or its individual components catechin and epicatechin, was compared with samples stabilized with a mixture of the synthetic antioxidants Irganox 1076 and Irgafos 168. Each sample was extruded and consecutively reextruded up to four times. The melt flow index (MFI) and the oxidation induction time (OIT) of the samples were measured after each step. The obtained results showed the interest of this natural matrix as a potential source of antioxidants for plastics <br> <br> <a target="_blank" href="http://onlinelibrary.wiley.com/doi/10.1002/app.33022/abstract"> Texto integral </a> <br> <br>

Abstract (EN): Several natural matrices were investigated as potential sources of antioxidants to be used as plastic additives. Extracts of four matrices obtained under the same experimental conditions were initially considered: green tea, black tea, Lippia citriodora and Hypericum androsaemum. Both, the antioxidant activity of the extracts and their content in flavanols and quercetin, were compared. The antioxidant activity was determined by DPPH analysis and the phenolic composition by high performance liquid chromatography (HPLC) using ultraviolet (UV) diode array and fluorescence (FL) detectors. Concentration of the flavanols reduced in the same way as their antioxidant activity starting with green tea, through black tea, Hypericum androsaemum, and Lippia citriodora. The performance of polypropylene samples stabilized with green tea extract, or its individual components catechin and epicatechin, was compared with samples stabilized with a mixture of the synthetic antioxidants Irganox 1076 and Irgafos 168. Each sample was extruded and consecutively reextruded up to four times. The melt flow index (MFI) and the oxidation induction time (OIT) of the samples were measured after each step. The obtained results showed the interest of this natural matrix as a potential source of antioxidants for plastics <br> <br> <a target="_blank" href="http://onlinelibrary.wiley.com/doi/10.1002/app.33022/abstract">Full text</a> <br> <br>

Language: English

Type (Professor's evaluation): Scientific