Supermolecular morphology of polypropylene filled with nanosized silica

Authors

  • Alois K. Schlarb,

    Corresponding author
    1. Composite Engineering, University of Kaiserslautern, Kaiserslautern, Germany
    2. Leibniz Institute for New Materials, Saarbrucken, Germany
    3. Research Center for Optics and Materials Sciences, University of Kaiserslautern, Kaiserslautern, Germany
    Search for more papers by this author
  • Dwi N. Suwitaningsih,

    1. Composite Engineering, University of Kaiserslautern, Kaiserslautern, Germany
    2. Research Center for Optics and Materials Sciences, University of Kaiserslautern, Kaiserslautern, Germany
    Search for more papers by this author
  • Michael Kopnarski,

    1. Research Center for Optics and Materials Sciences, University of Kaiserslautern, Kaiserslautern, Germany
    2. Institute for Surface and Thin Film Analysis, University of Kaiserslautern, Kaiserslautern, Germany
    Search for more papers by this author
  • Gereon Niedner-Schatteburg

    1. Research Center for Optics and Materials Sciences, University of Kaiserslautern, Kaiserslautern, Germany
    2. Cluster Chemistry Group, Department of Chemistry, University of Kaiserslautern, Kaiserslautern, Germany
    Search for more papers by this author

ABSTRACT

The supermolecular morphology of injection-molded SiO2/polypropylene (PP) nanocomposites was investigated via thin sections analyzed under polarized light and the systematic development of an appropriate etching technique, which allowed the study of the supermolecular morphologies with light microscopy (LM) and high-resolution field emission scanning electron microscopy (FESEM). In parallel, information regarding the dispersion, distribution state, and morphology of SiO2 particles was investigated via transmission electron microscopy (TEM) and scanning electron microscopy (SEM) of the ion-polished and fractured surfaces of SiO2-filled PP. The TEM/SEM results demonstrated an almost homogeneous dispersion and distribution of SiO2 particle agglomerates in the PP matrix. With polarized transmitting LM, reflecting LM, and FESEM, the spherulitic structure of the nanocomposites could be visualized to obtain information on the nanoparticle influence on the crystallization and structural behavior. The size and size distribution of the spherulites analyzed with transmitting light (thin sections) and reflecting light (etched specimens) showed an excellent correlation. With increasing filler loading, the mean size of the spherulites decrease as did the degree of crystallinity. This was a clear indication that the particles acted as nucleation agents and, on the other hand, hindered the arrangement of the molecules during the crystallization. As a result, the particles were most likely located in three areas: the center of the spherulites, the areas between the highly crystalline branches, and the spherulite boundaries. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39655.

Ancillary