Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene
The great concern about the use of hazardous additives in food packaging materials has shown the way to new bio-based materials, such as nanoclays incorporating bioactive essential oils (EO). One of the still unresolved issues is the proper incorporation of these materials into a polymeric matrix. T...
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MDPI AG
2021-02-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/11/2/474 |
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| author | Ioannis S. Tsagkalias Alexandra Loukidi Stella Chatzimichailidou Constantinos E. Salmas Aris E. Giannakas Dimitris S. Achilias |
| author_facet | Ioannis S. Tsagkalias Alexandra Loukidi Stella Chatzimichailidou Constantinos E. Salmas Aris E. Giannakas Dimitris S. Achilias |
| author_sort | Ioannis S. Tsagkalias |
| collection | DOAJ |
| description | The great concern about the use of hazardous additives in food packaging materials has shown the way to new bio-based materials, such as nanoclays incorporating bioactive essential oils (EO). One of the still unresolved issues is the proper incorporation of these materials into a polymeric matrix. The in situ polymerization seems to be a promising technique, not requiring high temperatures or toxic solvents. Therefore, in this study, the bulk radical polymerization of styrene was investigated in the presence of sodium montmorillonite (NaMMT) and organo-modified montmorillonite (orgMMT) including thyme (TO), oregano (OO), and basil (BO) essential oil. It was found that the hydroxyl groups present in the main ingredients of TO and OO may participate in side retardation reactions leading to lower polymerization rates (measured gravimetrically by the variation of monomer conversion with time) accompanied by higher polymer average molecular weight (measured via GPC). The use of BO did not seem to affect significantly the polymerization kinetics and polymer MWD. These results were verified from independent experiments using model compounds, thymol, carvacrol and estragol instead of the clays. Partially intercalated structures were revealed from XRD scans. The glass transition temperature (from DSC) and the thermal stability (from TGA) of the nanocomposites formed were slightly increased from 95 to 98 °C and from 435 to 445 °C, respectively. Finally, better dispersion was observed when orgMMT was added instead of NaMMT. |
| first_indexed | 2024-03-09T00:55:46Z |
| format | Article |
| id | doaj.art-993cfa056e9c4454a19aba057c036293 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-09T00:55:46Z |
| publishDate | 2021-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-993cfa056e9c4454a19aba057c0362932023-12-11T16:57:05ZengMDPI AGNanomaterials2079-49912021-02-0111247410.3390/nano11020474Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of StyreneIoannis S. Tsagkalias0Alexandra Loukidi1Stella Chatzimichailidou2Constantinos E. Salmas3Aris E. Giannakas4Dimitris S. Achilias5Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceDepartment of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceDepartment of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceDepartment of Material Science & Engineering, University of Ioannina, 45110 Ioannina, GreeceDepartment of Food Science and Technology, University of Patras, 30100 Agrinio, GreeceDepartment of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceThe great concern about the use of hazardous additives in food packaging materials has shown the way to new bio-based materials, such as nanoclays incorporating bioactive essential oils (EO). One of the still unresolved issues is the proper incorporation of these materials into a polymeric matrix. The in situ polymerization seems to be a promising technique, not requiring high temperatures or toxic solvents. Therefore, in this study, the bulk radical polymerization of styrene was investigated in the presence of sodium montmorillonite (NaMMT) and organo-modified montmorillonite (orgMMT) including thyme (TO), oregano (OO), and basil (BO) essential oil. It was found that the hydroxyl groups present in the main ingredients of TO and OO may participate in side retardation reactions leading to lower polymerization rates (measured gravimetrically by the variation of monomer conversion with time) accompanied by higher polymer average molecular weight (measured via GPC). The use of BO did not seem to affect significantly the polymerization kinetics and polymer MWD. These results were verified from independent experiments using model compounds, thymol, carvacrol and estragol instead of the clays. Partially intercalated structures were revealed from XRD scans. The glass transition temperature (from DSC) and the thermal stability (from TGA) of the nanocomposites formed were slightly increased from 95 to 98 °C and from 435 to 445 °C, respectively. Finally, better dispersion was observed when orgMMT was added instead of NaMMT.https://www.mdpi.com/2079-4991/11/2/474polymerization kineticspolystyreneNa-montmorilloniteorgano-modified montmorillonitethyme oiloregano oil |
| spellingShingle | Ioannis S. Tsagkalias Alexandra Loukidi Stella Chatzimichailidou Constantinos E. Salmas Aris E. Giannakas Dimitris S. Achilias Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene Nanomaterials polymerization kinetics polystyrene Na-montmorillonite organo-modified montmorillonite thyme oil oregano oil |
| title | Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene |
| title_full | Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene |
| title_fullStr | Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene |
| title_full_unstemmed | Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene |
| title_short | Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene |
| title_sort | effect of na and organo modified montmorillonite essential oil nanohybrids on the kinetics of the in situ radical polymerization of styrene |
| topic | polymerization kinetics polystyrene Na-montmorillonite organo-modified montmorillonite thyme oil oregano oil |
| url | https://www.mdpi.com/2079-4991/11/2/474 |
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