| Project/Area Number |
19K03761
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 13040:Biophysics, chemical physics and soft matter physics-related
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| Research Institution | Yamagata University |
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Principal Investigator |
Sukumaran S. K. 山形大学, 大学院有機材料システム研究科, 准教授 (70598177)
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| Co-Investigator(Kenkyū-buntansha) |
瀧本 淳一 山形大学, 大学院有機材料システム研究科, 教授 (50261714)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2021: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2019: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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| Keywords | Miscible Polymer Blends / Polymer Dynamics / Local Structure / Polymer Entanglements / Polymer Melts / Local Liquid Structure / Polymeric Liquids / Mixing Rule / Polymer Blends / Entanglements / Topological Analysis / Monomer size disparity |
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| Outline of Research at the Start |
As a paradigmatic example of the effect of topological constraints, monomer/chain size, and local packing on molecular motion, we will investigate the interplay between disparities in monomer size and chain stiffness, and composition fluctuations in determining the properties of entangled binary blends. Polymer blends were chosen because while they resemble both melts (Gaussian statistics, melt-like local packing, small density fluctuations) and solutions (large composition fluctuations, dynamical asymmetry, dilution), there are experimental indications that they are qualitatively different.
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| Outline of Final Research Achievements |
The major outcomes of the project are as follows: (1) Disparity in the size of monomers is sufficient for polymer blends to exhibit anomalous mixing for quantities related to entanglements, for instance the plateau modulus or equivalently, the tube diameter. We have verified this for blends of polymers that were nearly identical except their monomer sizes were either in the ratio 2:1 or 3:1. The local liquid-like structure of the blend was investigated using the radial distribution function (RDF). The RDF indicated that the mixing was nonrandom with an increased probability for the small monomers to be the non-bonded neighbors of the large monomers. We suspect that the origin of the anomalous mixing rules is related to this nonrandom mixing and efforts are underway to generalize the available mixing rules to account for this effect.
Surprisingly, we also found that the relaxation time of the large monomer chains increased and that of the small monomer chains decreased upon blending.
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| Academic Significance and Societal Importance of the Research Achievements |
Traditionally, the precise local liquid-like structure (monomer packing) is ignored in understanding the properties of dense polymeric liquids. Polymer blends with monomer size disparity present a major challenge to this view and suggest that concepts from liquid state physics are also necessary.
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