| 초록 |
Liquid crystalline polymers could be of different architectures; mesogenic units that impart the liquid crystalline property could be present either on the polymer backbone or as a pendant unit. The nature and property of the mesophase formed evidently depends on the polymer architecture, among other factors; the precise conformation of the polymer chain and its organization in bulk is rather difficult to probe experimentally, and the mesophase structure is most often characterised in terms of the organization of the mesogens. An interesting question that arises is: could the polymer be architechtured to control the nature of the mesophase formed? During the past decade, we have demonstrated that immiscibility between long segments, in suitably designed polymers, can be utilized to control the polymer chain conformation;1-3 zigzag folding of the polymer chain was shown to occur to enable the segregation and collocation of immiscible segments in periodically grafted amphiphilic copolymers (PGAC), often leading to the formation of lamellar morphoplogy assisted by the crystallization of either one or both the segments. In the presentation, I shall describe our recent efforts to understand the behavior of a new class of periodically grafted liquid crystalline polymer (PGLCP); I shall explore the influence of various structural parameters, such as the location of the mesogen (pendant versus backbone), nature and length of the pendant immiscible segment, etc., on the mesopmoprhic behavior. (1) R. K. Roy, E. B. Gowd, and S. Ramakrishnan, Macromolecules, 45, 3063 (2012). (2) J. Mandal, S. K. Prasad, D. S. S. Rao, and S. Ramakrishnan, J. Am. Chem. Soc., 136, 2538 (2014). (3) S. Chanda and S. Ramakrishnan, Macromolecules, 49, 3254 (2016). |
