Molecular conformation dynamics and chemical shift anisotropy of high impact Polystyrene: temperature dependence and stress dependence studies


Citation

Fauzi Mohd Som, . and Chudek John A., . and Hunter Geoffrey, . Molecular conformation dynamics and chemical shift anisotropy of high impact Polystyrene: temperature dependence and stress dependence studies. pp. 169-182. ISSN 1511-1768

Abstract

Variable temperature and variable stress nuclear magnetic resonance spectroscopic and imaging studies are reported for a commercial sample of high impact polystyrene. Liquid nuclear magnetic resonance microscopy and solid state stray field imaging studies indicated that imposed stress affects the molecular chain dynamics only of the polybutadiene region and not of the polystyrene (PS) matrix. The molecular chain dynamics of the components of the composite were further studied by variable temperature relaxation time and chemical shift anisotropy (CSA) measurements. The variable temperature (30C - 210C) H spin-lattice relaxation time in the rotating frame (T1pH) studies showed that up to 160C the PS undergoes at least 2 different modes of motion while at 95C a change from asymmetric to axially symmetric in the CSA pattern of the aromatic ring 13C-H resonances revealed that the conformations of the phenyl rings are effectively locked below that temperature.


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Abstract

Variable temperature and variable stress nuclear magnetic resonance spectroscopic and imaging studies are reported for a commercial sample of high impact polystyrene. Liquid nuclear magnetic resonance microscopy and solid state stray field imaging studies indicated that imposed stress affects the molecular chain dynamics only of the polybutadiene region and not of the polystyrene (PS) matrix. The molecular chain dynamics of the components of the composite were further studied by variable temperature relaxation time and chemical shift anisotropy (CSA) measurements. The variable temperature (30C - 210C) H spin-lattice relaxation time in the rotating frame (T1pH) studies showed that up to 160C the PS undergoes at least 2 different modes of motion while at 95C a change from asymmetric to axially symmetric in the CSA pattern of the aromatic ring 13C-H resonances revealed that the conformations of the phenyl rings are effectively locked below that temperature.

Additional Metadata

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Item Type: Article
AGROVOC Term: Polystyrene
AGROVOC Term: Spinning
AGROVOC Term: Cutting
AGROVOC Term: Polarization
AGROVOC Term: Nuclear magnetic resonance spectroscopy
AGROVOC Term: Measurement
AGROVOC Term: Chloroform
AGROVOC Term: Liquids
AGROVOC Term: Temperature
AGROVOC Term: Time
Depositing User: Ms. Suzila Mohamad Kasim
Last Modified: 24 Apr 2025 06:28
URI: http://webagris.upm.edu.my/id/eprint/23301

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