A novel use of Ti‐POSS as initiator of L‐lactide ring‐opening polymerization |
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Authors: | Orietta Monticelli Dario Cavallo Sergio Bocchini Alberto Frache Fabio Carniato Alessandro Tonelotto |
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Institution: | 1. Dipartimento di Chimica e Chimica Industriale, Università di Genova, via Dodecaneso, 31, 16146 Genova, Italy;2. Dipartimento di Scienza dei Materiali e Ingegneria Chimica, Politecnico di Torino ‐ sede di Alessandria, viale Teresa Michel, 5, 15121 Alessandria, Italy;3. Dipartimento di Scienze e Tecnologie Avanzate and Nano‐SISTEMI Interdisciplinary Centre, Università del Piemonte Orientale ‘A. Avogadro’, Viale Teresa Michel, 11, 15121 Alessandria, Italy |
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Abstract: | The efficacy of a metal‐silsesquioxane, namely, heptaisobutyl (isopropoxyde)titanium‐polyhedral oligomeric silsesquioxanes (Ti‐POSS), as initiator of the ring‐opening polymerization of L ‐lactide (LLA) has been assessed. Indeed, as demonstrated by proton nuclear magnetic resonance (1H NMR) spectroscopy and gel permeation chromatography (GPC) measurements, a well‐controlled polymerization occurs via a coordination‐insertion mechanism. Moreover, the above reaction leads to the direct insertion of the silsesquioxane molecule into the polymer backbone, thus producing a hybrid system. Differential scanning calorimetry measurements demonstrated that in comparison with a commercial poly‐L ‐lactide (PLLA), the polymers prepared with Ti‐POSS exhibit a higher crystallinity. Indeed, the presence of silsesquioxane molecules, attached to one end of the polymer chains, has been found to appreciably affect the crystal nucleation density. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 |
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Keywords: | M‐POSS PLA ring‐opening polymerization |
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