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Accessing the hidden lamellar nanostructure of semi‐crystalline nascent polymers by small‐angle X‐ray scattering contrast variation
Author(s) -
Westfahl Jr Harry,
Cardoso Mateus Borba
Publication year - 2011
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889811033255
Subject(s) - small angle x ray scattering , lamellar structure , scattering , materials science , nanostructure , polymer , amorphous solid , crystallography , optics , chemical physics , stacking , nanotechnology , chemistry , composite material , physics , organic chemistry
Most melt‐crystallized polymers present a lamellar nanostructure of alternating crystalline and amorphous lamellae which is coherent enough to display a broad interference peak in small‐angle X‐ray scattering experiments (SAXS). Nascent semi‐crystalline polymers, on the other hand, though highly crystalline, hardly show an interference peak. This has long been attributed either to the formation of extended chain crystals or to a highly incoherent lamellar stacking. Here it is shown that a coherent lamellar order is shaded by a large scattering contribution from the air/grain interface. This is revealed by a SAXS contrast variation technique that suppresses the air/grain interface scattering and leaves only the scattering contribution from the internal lamellae.