Quantum vibration dynamics and deformation of skeleton of polymer molecules

• Published in: Polymer science. Series A, Chemistry, physics Chemistry, physics, 2009-08, Vol.51 (8), p.849-857
• Main Authors: Vettegren’, V. I., Kulik, V. B.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Journal Jubilee; Polymer Sciences
• ISSN: 0965-545X; 1555-6107
• DOI: 10.1134/S0965545X0908001X

The results of investigation on the temperature dependences of strain of the regularly constructed fragments of the carbon skeleton in linear polymers are reviewed. Stretching of the skeleton is induced under the action of twisting and bending vibrations when both ends of an oscillating chain fragment are fixed. In this case, the anharmonic character of vibrations plays no key role. At temperatures T t and T b , the statistics of atomic vibrations changes from quantum to classical, and the slope of the corresponding temperature dependences changes as well. At T < T t , vibrations are not excited, and the skeleton is extended owing to zero-point vibrations. At T t , twisting vibrations are induced, and a skeleton of the molecules is extended with temperature linearly. At T b , bending vibrations are activated, and the slope of the temperature dependences of the strain of the skeleton increases. Additional stretching and an increased amplitude of vibrations of the skeleton carbon atoms are provided owing to the scattering of stretching vibrations at the boundaries of crystals.