Počet záznamů: 1  

Cyclic olefin copolymer-silica nanocomposites foams

  1. 1. 0456137 - UMCH-V 2017 RIV US eng J - Článek v odborném periodiku
    Pegoretti, A. - Dorigato, A. - Biani, A. - Šlouf, Miroslav
    Cyclic olefin copolymer-silica nanocomposites foams.
    Journal of Materials Science. Roč. 51, č. 8 (2016), s. 3907-3916. ISSN 0022-2461
    Grant CEP: GA MŠk(CZ) LO1507
    Institucionální podpora: RVO:61389013
    Klíčová slova: cyclic olefin copolymer * nanocomposites * silica
    Kód oboru RIV: CD - Makromolekulární chemie
    Impakt faktor: 2.599, rok: 2016

    A cyclic olefin copolymer (COC) matrix was melt compounded with various amounts of fumed silica nanoparticles (1, 3 and 5 vol%) and the resulting materials were foamed through supercritical carbon dioxide. Foams were produced at four different foaming pressures (90, 110, 130, and 150 bar), keeping all other processing parameters constant. The main physical properties of both bulk and foamed samples were investigated in order to assess the role of both nanofiller content and foaming pressure. It was observed that the density values of the foamed materials decreased as the foaming pressure increased and that the presence of nanofillers leads to slightly denser materials. Both scanning and transmission electron microscopy evidenced the presence of filler aggregates on the bulk composites. These aggregates resulted to be elongated along the cell wall direction upon foaming. Dynamic mechanical thermal analysis, quasi-static tensile tests, and creep tests evidenced a positive effect played by nanosilica in improving the stiffness, the strength, and the creep stability of the polymer matrix for all foaming pressures. The application of a theoretical model for closed-cell foams highlighted how the stiffening effect provided by the nanosilica networking is mostly effective at elevated filler amounts and reduced foaming pressure values.
    Trvalý link: http://hdl.handle.net/11104/0256722