Author: Мастюгинс

Specialization: 010700 Physics of condensed matter
Program: 11 Physics of polymers and liquid crystals
Program director: Prof. Е.I. Rjumtsev
Department of Polymer Physics
Scientific supervisor: assistant professor S.G.Polushin 
Referee: assistant professor I.P. Kolomiets

Kerr effect in smectic polymer melts.
Mastiugin Alexander
The research is connected with the study of pre-transitional phenomena in isotropic melt which are caused by the short-range order. As known, Kerr constant and the relaxation time of induced order in isotropic melt change steadily being close to the achieving transition isotropic - liquid crystal phase, the constant and relaxation time prolong close to the phase transition. Lately the effect of rapid change of temperature dependence K was recorded in the melt of methacrylic polymer with chiral side groups. This effect was rendered as the transition isotropic phase - isotropic phase. These transitions have recently been recorded in isotropic phase of low-molecular weight substances with the methods of calorimetry and dielectric spectroscopy. Transitions occurred in chiral smectic polymer systems. The paper includes the study of electro-optical properties of two comb smectic polyacrylates: so-polymer with cyanobiphyl side groups and so-polymer containing monomer units of three kinds (mesogenic cyanobiphyl groups, carboxyl groups and alkali metal). The characteristic curve of Kerr constant and temperature was recorded, limiting temperature of isotropic phase existence (the temperature of divergence) T* was stated The existence of the transition isotropic phase - isotropic phase was first recoded in no-chiral polymer. The study of the dynamics of electro-optical effect after the turn-off of the field was carried out. Finally, a complex characteristic curve of integral time of relaxation from temperature and the existence of relaxation time spectum was shown.