The Influence of Freeze-Dried Alcohol-Water Extracts from Common Yarrow (<i>Achillea millefolium</i> L.) and German Chamomile (<i>Matricaria chamomilla</i> L.) on the Properties of Elastomer Vulcanizates
This research work aimed to investigate the properties of freeze-dried extracts from <i>Matricaria chamomilla</i> L. and <i>Achillea millefolium</i> L. and to perform a characterization of their impact on the natural rubber-based vulcanizates. First, extracts were prepared in...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-11-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/23/23/15048 |
| Summary: | This research work aimed to investigate the properties of freeze-dried extracts from <i>Matricaria chamomilla</i> L. and <i>Achillea millefolium</i> L. and to perform a characterization of their impact on the natural rubber-based vulcanizates. First, extracts were prepared in three different solvents at selected volume ratios: water (100), water-methanol (50/50), and water-ethanol (50/50). Next, the freeze-drying of extracts was established and then obtained bio-additives were introduced to the rubber mixtures. Freeze-dried extracts were investigated by UV-VIS diffuse reflectance spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Near-Infrared spectroscopy (NIR) and thermogravimetric analysis (TGA). Antioxidant activity and total phenolic content (TPC) were also defined. Rubber mixtures were examined in a rheometer and after vulcanization they were subjected to accelerated simulated aging by UV radiation and thermo-oxidative aging. To determine the resistance of vulcanizates to the degradation processes, the study of cross-linking density (equilibrium swelling method), mechanical properties (tensile strength, elongation at break) and color change were conducted. Performed studies proved the antioxidant activity of freeze-dried extracts caused by the high content of polyphenols and their beneficial influence on the properties of elastomer vulcanizates. |
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| ISSN: | 1661-6596 1422-0067 |