Technical Physics Letters, Vol. 27, No. 5, 2001, pp. 351–353. Translated from Pis’ma v Zhurnal Tekhnicheskoœ Fiziki, Vol. 27, No. 9, 2001, pp. 1–7. Original Russian Text Copyright © 2001 by Pozdnyakov, Redkov, Egorov. A Mass-Spectrometric Study of the Behavior of Thermotropic Liquid-Crystalline Polymers on Heating O. F. Pozdnyakov, B. P. Redkov, and E. A. Egorov Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg, 194021 Russia e-mail:
[email protected] Received October 31, 2000 Abstract—Physicochemical processes accompanying the thermal treatment of a liquid-crystalline aromatic copolyester Ultrax-4002 at temperatures in the vicinity of the thermotropic transition were studied by mass spectrometry in order to reveal possible features of the mechanism of polymer strengthening. It is shown that the thermal treatment leads to additional polycondensation in the material and the degradation of macro- molecules with the accumulation of low-molecular-mass products in the polymer bulk. The energy parameters of the polycondensation, thermal degradation, and diffusion processes were determined. © 2001 MAIK “Nauka/Interperiodica”. The unique combination of the thermal and mechan- many). The molar fractions of the fragments of tere- ical properties of thermotropic liquid-crystalline (LC) and isophtalic acids and p,p-dioxybisphenol in macro- polymers naturally attracts the attention of researchers. molecules of this polymer [4] are 0.25, 0.25, and 0.5, A high thermal stability of these LC polymers, together respectively. The chemical formula of the polymer with good mechanical strength, makes these materials chain unit is as follows: highly promising for various applications [1–5].