Lamellar Thickness of a Syndiotactic Polystyrene Determined from Small-angle X-ray Scattering and Transmission Electron Microscopy

Extensive morphological studies on a syndiotactic polystyrene (sPS) sample prepared from compression molding were carried out using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). SAXS was conducted at 25^sup ^C as well as at 150^sup ^C to enhance the scattering contr...

Full description

Saved in:
Bibliographic Details
Published in:Journal of polymer research 2002-06, Vol.9 (2), p.91-96
Main Authors: Liao, Wei-po, Lin, Tsang-lang, Woo, E M, Wang, Chi
Format: Article
Language:English
Subjects:
Electron microscopy
Lamellar structure
Mineralogy
Polystyrene resins
SAXS
Scattering
Small angle X ray scattering
Syndiotacticity
Transmission electron microscopy
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Extensive morphological studies on a syndiotactic polystyrene (sPS) sample prepared from compression molding were carried out using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). SAXS was conducted at 25^sup ^C as well as at 150^sup ^C to enhance the scattering contrast in order to obtain more reliable morphological parameters. The compression-molded sample was crystallized into a β' orthorhombic crystal lattice characterized by wide-angle X-ray diffraction (WAXD). A similar weight fraction of crystallinity, ca. 0.37, was obtained from both WAXD and differential scanning calorimetry measurements. In addition to the scattering peak at a scattering vector of ca. 0.36 nm^sup -1^ attributable to the presence of lamellar/amorphous layers, anomalous scattering at the zero angle was found from the SAXS intensity profiles. Based on the Debye-Bueche theory, the scattering profile of this peculiar zero-angle scattering was deduced and was subtracted from the raw intensity profile to obtain the intensity profile exclusively associated with the lamellar/amorphous structure. A consistent long period was obtained for SAXS measured either at 25 or 150^sup ^C, provided that the appropriate subtraction of intensities due to the zero-angle scattering was conducted. Moreover, the lamellar thickness deduced from the one-dimensional correlation function was in good agreement with TEM results. A "difference scattering" pattern derived from SAXS measured at 150 and 25^sup ^C was obtained and a comparison of the morphological parameters was provided as well.[PUBLICATION ABSTRACT]
ISSN:1022-9760
1572-8935
DOI:10.1023/A:1021133732704