Synthesis,Characterization and Properties of (Vinyl Triethoxy Silane-grafted PP)/Silica Nanocomposites |
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Authors: | S Jain JGP Goossens M van Duin |
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Institution: | 1. Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands
Dutch Polymer Institute, PO Box 902, 5600 AX Eindhoven, The Netherlands;2. DSM Research, PO Box 18, 6160 MD Geleen, The Netherlands |
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Abstract: | A new route has been developed to produce PP/silica nanocomposites starting from porous PP reactor powder and making use of sol-gel chemistry. Silica-like, nano-sized particles were prepared in the pores of the PP reactor powder with a controlled degree of adhesion between PP and silica. Magic-angle spinning (MAS) 29Si NMR spectra showed that the chemical building blocks of the silica-like clusters are of Q3 and Q4-type. For (vinyl triethoxy silane (VTES)-grafted PP)/silica nanocomposites, VTES was grafted via solid-state modification (SSM) in porous PP particles. Subsequently, silica particles were prepared by sol-gel technology in the VTES-grafted PP. MAS 29Si NMR and FT-IR spectroscopy showed that the grafted VTES becomes part of the in-situ formed silica particles. The study on the mechanical properties of (VTES-grafted PP)/silica nanocomposites showed that the silica particles improved the impact toughness of PP by a factor of 2, when there is no chemical interaction between the particles and the matrix, while for (VTES-grafted PP)/silica nanocomposites the impact toughness decreased. This indicates that chemical bonding between the filler particles and the PP-matrix results in brittle failure and supports the hypothesis that debonding is necessary for improving the impact toughness of PP with inorganic fillers. |
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Keywords: | Crystallization Grafting Mechanical properties Nanocomposites Polypropylene |
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