Oriented Structure in Isotactic Polystyrene Melt Induced by Shear Flow

We performed polarized optical microscope (POM), depolarized light scattering (DPLS) and small-angle X-ray scattering measurements on the structure formation process or the crystallization process of isotactic polystyrene (iPS) under shear flow below and above the nominal melting temperature Tm. It...

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Bibliographic Details
Published in:KOBUNSHI RONBUNSHU 2009, Vol.66(10), pp.419-427
Main Authors: MATSUBA, Go, ZHAO, Yunfeng, TERATANI, Makoto, HAYASHI, Yuji, TAKAYAMA, Yoshiyuki, OGINO, Yoshiko, NISHIDA, Koji, KANAYA, Toshiji
Format: Article
Language:Japanese
Subjects:
Crystallization
Isotactic Polystyrene
Microscope
Precursor
Shear Flow
Shish-Kebab
X-ray Scattering
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Summary:We performed polarized optical microscope (POM), depolarized light scattering (DPLS) and small-angle X-ray scattering measurements on the structure formation process or the crystallization process of isotactic polystyrene (iPS) under shear flow below and above the nominal melting temperature Tm. It was found that a micron scale anisotropic oriented structure termed here as “string-like object” was formed even above the nominal melting temperature that is stable for more than 24 h, but melted at around 270°C far above the nominal melting temperature. The string-like object acts as a nucleation agent for the folded chain lamella crystal (or the kebab). We also examined the shear rate dependence of the structure formation to find a critical shear rate and a critical strain for the formation of the string-like object, suggesting the orientation and relaxation of the chains plays an important role in the formation of the structure.
ISSN:0386-2186
1881-5685
DOI:10.1295/koron.66.419