Role of hydrogen peroxide in selective OH group functionalization of polypropylene surfaces using underwater capillary discharge
- Plasma chemical methods are well suited for introducing functional groups to the surfaces of chemically inert polymers such as polyolefins. However, a broad variety of functional groups are often formed. Unfortunately, for further chemical processing such as grafting of molecules for advanced applications a highly dense monotype functionalized polyolefin surface is needed. Therefore, the main task was to develop a selective surface functionalization process, which formed preferably only a single type of functional groups at the surface in high concentration. Amongst the novel plasma methods, the underwater plasma process (UWP) is one of most attractive options to solve the problem of monotype functionalization. Such plasma is an efficient source of ions, electrons, UV-radiation, high-frequency shock waves, radicals such as hydroxyl radical, and reactive neutral molecules such as hydrogen peroxide. In contrast to established gas phase glow discharge processes, the water phase limits thePlasma chemical methods are well suited for introducing functional groups to the surfaces of chemically inert polymers such as polyolefins. However, a broad variety of functional groups are often formed. Unfortunately, for further chemical processing such as grafting of molecules for advanced applications a highly dense monotype functionalized polyolefin surface is needed. Therefore, the main task was to develop a selective surface functionalization process, which formed preferably only a single type of functional groups at the surface in high concentration. Amongst the novel plasma methods, the underwater plasma process (UWP) is one of most attractive options to solve the problem of monotype functionalization. Such plasma is an efficient source of ions, electrons, UV-radiation, high-frequency shock waves, radicals such as hydroxyl radical, and reactive neutral molecules such as hydrogen peroxide. In contrast to established gas phase glow discharge processes, the water phase limits the particle and radiation energies and thus the energy input into the polymer. By virtue of the liquid water environment, which moderates highly energetic plasma species, extensive oxidation, degradation, cross-linking and radical formation on the polymer are more limited as compared to gas plasma exposure. The variety of plasma produced species in the water phase is also much smaller because of the limited reaction possibilities of the plasma with water. The possibility to admix a broad variety of chemical additives makes underwater plasma even more attractive. Hydrogen peroxide and the catalyst (Fe-ZSM5) should influence and increase the equilibrium concentration of OH radicals in the underwater plasma process. It was found that these radicals played a very important role in OH functionalization of polyolefin surfaces. Hydrogen peroxide was identified to be the most prominent precursor for OH group formation in the UWP. The catalyst would affect the steady state of OH radical formation and its reaction with the substrate surface and thus accelerates the functionalization process.…
MetadatenAutor*innen: | Ranjit Joshi, Jörg Florian Friedrich, M. Wagner |
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Dokumenttyp: | Zeitschriftenartikel |
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Veröffentlichungsform: | Verlagsliteratur |
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Sprache: | Englisch |
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Titel des übergeordneten Werkes (Englisch): | Journal of adhesion science and technology |
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Jahr der Erstveröffentlichung: | 2011 |
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Verlag: | VNU Science Press |
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Verlagsort: | Utrecht |
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Jahrgang/Band: | 25 |
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Erste Seite: | 283 |
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Letzte Seite: | 305 |
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Freie Schlagwörter: | Capillary discharge; Fenton-like processes; Heterogeneous catalysis; Hydrogen peroxide; Hydroperoxyl radicals; Hydroxyl functionalization; Polymer functionalization; Surface modification; Underwater plasma |
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DOI: | 10.1163/016942410X520862 |
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ISSN: | 0169-4243 |
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ISSN: | 1568-5616 |
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Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
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Datum der Freischaltung: | 19.02.2016 |
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Referierte Publikation: | Ja |
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Datum der Eintragung als referierte Publikation: | 18.11.2010 |
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