S. Yan et al., Epitaxial and graphoepitaxial growth of isotactic polypropylene (iPP) fromthe melt on highly oriented high density polyethylene (HDPE) substrates, J POL SC PP, 37(15), 1999, pp. 1893-1898
Although under normal conditions only the crystallization behavior of PE on
oriented IPP substrates can be studied due to the higher melting point of
iPP, the faster crystallization rate of a molten, oriented HDPE film compar
ed to a nonoriented IPP layer was used to study the crystallization of iPP
on the oriented HDPE film by means of transmission electron microscopy (TEM
) and electron diffraction (ED). Besides the known epitaxial relationship o
f HDPE/iPP with their chains 50 degrees apart, two new orientation relation
ships with (a) chains of both polymers parallel and (hk0)(iPP) in contact w
ith the HDPE substrate, and (b) the a-axis of iPP crystals parallel to the
chain direction of HDPE but (001)(iPP) in contact with the HDPE substrate w
ere observed. Both orientations are assumed as graphoepitaxy. (C) 1999 John
Wiley & Sons, Inc.