Development of Synchrotron DSC/WAXD/SAXS Simultaneous Measurement System for Polymeric Materials at the BL40B2 in SPring-8 and its Application to the Study of Crystal Phase Transitions of Fluorine Polymers

Abstract

ABSTRACT:A new system of rapidly-scanning DSC/WAXD/SAXS simultaneous measurements has been successfully developed at the BL40B2 in SPring-8, Japan. The combination of the ultra-bright and highly-directional X-ray beams with the highly-sensitive two-dimensional (2D) detectors such as an imaging plate (IP), a CCD detector and a flat panel (FP) detector has made it possible to perform the rapidly-scanning time-resolved measurements of WAXD and SAXS for the polymeric materials subjected to the various kinds of external field like temperature, tensile force, magnetic field, hydrostatic pressure, and so on. The experimental data about the phase transitions of vinylidene fluoridetrifluoroethylene copolymer with VDF 82 mol % content and poly(vinylidene fluoride) form I have been presented as actual examples, where the phase transitions of the polar crystal consisting of planar-zigzag chains to the gauche-type high-temperature phase have been confirmed definitely and the remarkable change in lamellar stacking structure could be detected in the temperature region immediately below the melting point. [doi:10.1295/polymj.PJ2007105] KEY WORDS Simultaneous Measurement System / Wide-angle X-ray Diffraction / Small-angle X-ray Scattering / Differential Scanning Calorimetry / SPring-8 / Poly(vinylidene fluoride) / Phase Transition / Polymeric materials consist of complicated aggregation state of chains. In the case of semicrystalline polymer, for example, these chains gather together to form the crystalline region or a crystalline lamella. These lamellae are stacked together to construct a spherulite. There are amorphous region between these stacked lamellae. In the spherulite, the lamellae extend and twist periodically from the spherulitic center along the radial direction, giving the so-called extinction ring in its polarized optical microscopic image. It is essentially important to clarify the evolution process of this complicated hierarchical structure of polymers from the various viewpoints on angstrom-tomicrometer scale in order to design and control their physical and structural properties. One of the most useful and quantitative methods for attainment of this purpose is to use the X-ray scattering technique. The wide-angle X-ray diffraction (WAXD) gives us information on the chain conformation and the aggregation state of chains in the crystalline and amorphous regions. The small-angle X-ray scattering (SAXS) tells us about the rough form of molecular chains, the aggregation structure of crystalline lamellae, and so on. Therefore, the time-resolved measurements of WAXD and SAXS allow us to trace the structural evolution process of polymers in the heating or cooling process, for example. There were many reports on the WAXD and/or SAXS experimental data.1 In most cases the WAXD or SAXS measurement was performed for a sample separately by assuming the reproducibility of the experimental conditions. But, strictly speaking, we do not have any guarantee about the reproducibility of the experimental conditions in the WAXD and S...

Correlation of Structure Changes in the Water-Induced Phase Transitions of Poly(ethylenimine) Viewed from Molecular, Crystal, and Higher-Order Levels As Studied by Simultaneous WAXD/SAXS/Raman Measurements

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Nanostructure development in multicomponent polymer systems characterized by synchrotron X-ray scattering

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Competition of PEG coverage density and con-A recognition in mannose/PEG bearing nanoparticles

“…Synchrotron SAXS Measurements: SAXS measurements were performed at BL-40B2 of SPring-8, Japan. [17] A 30 cm  30 cm imaging plate (Rigaku R-AXIS VII; Tokyo, Japan) detector was placed at 1.65 m from the sample. The wavelengths of the incident beam () were 0.10 nm.…”