Local intramolecular mobility in regular linear polyesters with exible siloxane and more rigid ester aromatic fragments providing in some cases LC state was studied by dielectric spectroscopy. The dielectric transitions related to the local mobility in the ester aromatic fragment were observed. It was shown that two local relaxation processes (b 0 and b 00 ) with different mechanisms of mobility took place in these systems. One of them, the b 00 process, having the shortest relaxation times (t , 10 27 s) is connected with the motion of ester groups and phenyl rings. It is determined only by intramolecular interactions. The second local process, b 0 , re¯ects the motion of the polar ester group including the central part of the ester aromatic fragment (t , 10 21±10 24 s). This motion can be realized at the beginning of ¯ipping of the aromatic ring. Parameters of the b 0 process depend on intra- and intermolecular interactions.
Посилання на статтю:
Local intramolecular mobility in linear polyesters simulating the structure of thermotropic polymers / L.L. Burshtein, T.I. Borisova, S.V. Zhukov, N.A. Nikonorova, D.N. Asinovskaya, // Polymer. – 1999. – N 40. – P. 1881–1887.