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

Валерий Александрович Рыжов

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 ”.

Аннотация

Abstract.

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.