Conclusion

Abstract

The liquid-crystalline state of polymers, which has been intensely studied in the last 10–15 years, has become a rule rather than an exception for macro-molecular systems of different classes. Despite the fact that both linear and branched polymers which differ in chemical structure, chain rigidity, stereo-regularity, the capacity for crystallization, etc. are included in the class of liquid-crystal polymers, there is also a common cause giving rise to the formation of LC polymer phases. This cause is either the elevated rigidity of the macro-molecules as a whole or extensive segments of them. For this reason, in generalizing the material reported in this monograph for very different polymer systems, it is possible to use the ratio of the length of the statistical segment or characteristic molecular fragment to the diameter, X = l/d, which determines the critical concentration of the phase transition φA/X, where A is a constant equal to 5–10, as the criterion of the transition into the mesomorphic state (we will use the more neutral term than LC).