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Synthesis and Characterization of Thermotropic Liquid Crystalline Poly(ester‐imide)s
Author(s) -
Kim Tae Kyun,
Kim Sang Ouk,
Chung In Jae
Publication year - 1997
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/(sici)1099-1581(199705)8:5<305::aid-pat650>3.0.co;2-6
Subject(s) - thermotropic crystal , materials science , imide , substituent , crystallinity , polymer chemistry , polymer , liquid crystal , monomer , polymerization , copolymer , liquid crystalline , organic chemistry , composite material , chemistry , optoelectronics
A series of thermotropic liquid crystalline poly(ester‐imide)s was synthesized by melt polymerization of diacetoxynaphthalene acid and n ‐(ω‐carboxyalkylene) trimellitic imides. All polymers with 2,6 substituent positions ( n ‐2,6 PEIM) on the napthalene ring exhibit liquid crystalline phases, whereas polymers with 2,7 substituent positions ( n ‐2,7 PEIM) do not. This result suggests that the kink structure of n ‐2,7 PEIMS would hinder the formation of liquid crystalline polymer. The copoly(ester‐imide)s with an irregular sequence of aliphatic units and aromatic mesogens showed the liquid crystallinity with the lower transition temperatures and a lesser tendency to crystallize than homopoly(ester‐imide)s. The semicrystalline polymers with more regular monomeric sequence in the main chain showed the hysteresis of viscoelastic property in the temperature cycle. A nematic glassy copolymer gave the higher molecular orientation to the fiber than a semicrystalline polymer. © 1997 John Wiley & Sons, Ltd.