Assignments of Low-Frequency Vibrational Modes of Crystalline Polymers by Using a Fragment Method and Analysis of the Higher-Order Structures

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K17860
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Polymer chemistry; Analytical chemistry
• Research Institution: Osaka University
• Principal Investigator: Yamamoto Shigeki 大阪大学, 理学研究科, 助教 (60552784)
• Research Collaborator: OZAKI Yukihiro ; SATO Harumi ; HOSHINA Hiromichi
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: 高分子構造 / スペクトル分析

Outline of Final Research Achievements

It is important to analyze the higher-order structures of crystalline polymers in relation to their structures and functions. The low-frequency vibrational spectroscopies are sensitive to the polymer structures and can be simple analytical methods of them. However, the low-frequency modes haven’t been fully assigned yet. Here, we successfully developed a low-frequency Raman spectrometer and achieved the assignments of the low-frequency modes of nylon 6, a typical crystalline polyamide, by applying a fragment-based DFT calculation to the spectral interpretation.

Free Research Field

振動分光

Academic Significance and Societal Importance of the Research Achievements

結晶性ポリマー，特に繊維素材として使用されることの多いナイロン6の低波数振動モードを，独自の量子力学計算に基づいて帰属できたことは，世界的に見て新しく，重要な成果である。ナイロン6の低波数振動ピークの強度はナイロン6結晶の面間隔と相関するが，その原因をピーク帰属に基づいて推測することができた。今後，低波数振動分光を，結晶性ポリマーの高次構造を解析する簡便な分析手法として使用する際に，今回得られた帰属は必須の情報となるであろう。