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Site‐resolved X‐ray scattering studies, I investigations on plates from PP‐graphite composites
Author(s) -
Zipper Peter,
Chernev Boril,
Schnetzinger Karl
Publication year - 2002
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/1521-3900(200205)181:1<411::aid-masy411>3.0.co;2-a
Subject(s) - graphite , materials science , composite material , crystallite , scattering , tacticity , goniometer , crystallography , optics , polymer , chemistry , physics , metallurgy , polymerization
Cross‐sections cut from rectangular plates injection or compression‐molded from composites of isotactic polypropylene and varying amounts (up to 40 mass%) of different grades of graphite were investigated by site‐resolved wide‐angle X‐ray scattering (WAXS), using a two‐circle goniometer and a specially adapted Kratky camera, respectively. The measurements yielded detailed information about the orientation of both the filler particles and the PP crystallites, in dependence on the position in the cross‐sections. In the plates molded from composites, the graphite particles are preferentially oriented with their (002) planes parallel to the surface of the plates and the α‐PP crystallites prefer the same orientation for their (040) planes. In plates devoid of graphite, the PP crystallites show a different orientation behavior, however, the presence of 0.2% graphite is already sufficient to change the orientation to the afore‐mentioned mode. The observed parallelism in the preferential orientation of the graphite particles and the PP matrix suggests the assumption of hetero‐epitaxial growth of α‐PP crystallites on the (002) surface of oriented graphite particles. According to our results, the effects of the PP‐graphite interaction are dependent on the nature and properties of the graphite particles and may be modulated by treating the graphite surface with different coatings.