Molecular Basis of the Shish-Kebab Morphology in Polymer Crystallization
Shuichi Kimata,1,2
Takashi Sakurai,1
Yoshinobu Nozue,1*
Tatsuya Kasahara,1
Noboru Yamaguchi,1
Takeshi Karino,3
Mitsuhiro Shibayama,3
Julia A. Kornfield2*
In the rich and long-standing literature on the flow-induced
formation of oriented precursors to polymer crystallization,
it is often asserted that the longest, most extended chains
are the dominant molecular species in the "shish" of the "shish-kebab"
formation. We performed a critical examination of this widely
held view, using deuterium labeling to distinguish different
chain lengths within an overall distribution. Small-angle neutron-scattering
patterns of the differently labeled materials showed that long
chains are not overrepresented in the shish relative to their
concentration in the material as a whole. We observed that the
longest chains play a catalytic role, recruiting other chains
adjacent to them into formation of the shish.
2 Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
3 The Institute for Solid State Physics, The University of Tokyo, Tokai, Naka-gun, Ibaraki 319-1106, Japan.
* To whom correspondence should be addressed. E-mail: nozue{at}sc.sumitomo-chem.co.jp (Y.N.); jak{at}caltech.edu (J.A.K.)
