«Universal features of the manifestation of the relationship between local and segmental dynamics of polymers at terahertz frequencies in IR spectra»

  • Валерий Александрович Рыжов ФТИ им. А.Ф.Иоффе
Ключевые слова: Keywords: IR spectra, excess density of vibrational states, bosonic peak, molecular dynamics, α- and β-relaxations., Список специальных терминов с указанием их английских эквивалентов: «сегментальная динамика» - “segmental dynamics ”; «релаксационные потери»- “ relaxation losses ”; «механизм Поли»- “ Poley mechanism ”; «избыточная плотность колебательных состояний »- “ excess density of vibrational states”; «перегиб»- “ shoulder ”; «полоса либрации»- “the librational band ”.




Low-frequency IR- spectra of glassy polymers were obtained and analyzed at temperatures from 90 to 400K. Temperature changes in the IR- spectra in the range from 10 to 140 cm-1 show three universal features: low-temperature, corresponding to the torsional-vibrational motion of monomer units, high-temperature, due to the influence of primary relaxation (glass transition) and intermediate, caused by the activation of conformational mobility in chains at a temperature of β - transition. This versatility extends both to polymers with universal chain-to-chain interactions and to those with hydrogen bonds.