Dynamics of a Supercooled Disordered Sphere-Forming Diblock Copolymer as Determined by X-ray Photon Correlation and Dynamic Mechanical Spectroscopies
| Autor: | Kyung-Tae Kim, Frank S. Bates, Mahesh K. Mahanthappa, Michael J. Maher, Suresh Narayanan, Timothy P. Lodge, Ronald M. Lewis, Grayson L. Jackson, Haley K. Beech |
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| Rok vydání: | 2022 |
| Předmět: |
Materials science
Polymers and Plastics Transition temperature Organic Chemistry Nucleation Thermodynamics 02 engineering and technology Dynamic mechanical analysis 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Isothermal process 0104 chemical sciences Inorganic Chemistry Dynamic light scattering Phase (matter) Materials Chemistry Relaxation (physics) 0210 nano-technology Supercooling |
| Zdroj: | ACS macro letters. 7(12) |
| ISSN: | 2161-1653 |
| Popis: | We report the dynamic behavior of a sphere-forming poly(styrene)-block-poly(1,4-butadiene) (PS–PB) diblock copolymer comprising 20 vol % PB below the order–disorder transition temperature (TODT = 153 °C) using dynamic mechanical spectroscopy (DMS) and X-ray photon correlation spectroscopy (XPCS). A time–temperature transformation diagram was constructed by monitoring the elasticity of the sample as a function of time following rapid quenches of the disordered melt to various temperatures T < TODT. Isothermal frequency spectra acquired prior to nucleation of the ordered BCC phase were time–temperature superposed, and the shift factors were fit using the Williams–Landel–Ferry (WLF) equation. For comparison, XPCS measurements were used to extract relaxation times from the supercooled liquid as a function of the quench temperature. Alignment of the temperature dependence of the XPCS-based relaxation times with that of the WLF shift factors in the range T = 125–140 °C indicates that both techniques probe the f... |
| Databáze: | OpenAIRE |
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