Molecular self-healing mechanisms between C60-fullerene and anthracene unveiled by Raman and two-dimensional correlation spectroscopy.
The self-healing polymer P(LMA-co-MeAMMA) crosslinked with C60-fullerene has been studied by FT-Raman spectroscopy in combination with two-dimensional (2D) correlation analysis and density functional theory calculations. To unveil the molecular changes during the self-healing process mediated by the Diels-Alder equilibrium between 10-methyl-9-anthracenyl groups and C60-fullerene different anthracene-C60-fullerene adducts have been synthesized and characterized by time-, concentration- and temperature-dependent FT-Raman measurements. The self-healing process could be monitored via the C60-fullerene vibrations at 270, 432 and 1469 cm(-1). Furthermore, the detailed analysis of the concentration-dependent FT-Raman spectra point towards the formation of anthracene-C60-fullerene adducts with an unusual high amount of anthracene bound to C60-fullerene in the polymer film, while the 2D correlation analysis of the temperature-dependent Raman spectra suggests a stepwise dissociation of anthracene-C60-fullerene adducts, which are responsible for the self-healing of the polymer.
Institute for Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany. juergen.popp@uni-jena.de.
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Geitner
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Kötteritzsch
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Siegmann
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Fritzsch
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Bocklitz
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Hager
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Schubert
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Gräfe
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Dietzek
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Schmitt
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Popp