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Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 23, Number 9
BKCSDE 23(9)
September 20, 2002 

 
Title
Synthesis and Liquid Crystalline Properties of Hyperbranched Aromatic Polyesters Consisting of Azoxybenzene Mesogens and Polymethylene Spacers
Author
Young Suk Park, Jun-Woo Lee, Jung-Il Jin
Keywords
Hyperbranched LCPs, Aromatic polyesters, Built-in mesogen, Degree of branching
Abstract
A new series of hyperbranched aromatic polyesters containing azoxybenzene mesogens and polymethylene spacers were prepared by polymerizing AB2 type monomers that have the isophthaloyl dicarboxylic acid terminal at one end and the p-oxyphenol terminal at the other end. The monomers contain a built-in azoxybenzene mesogen that is linked to the terminal groups through polymethylene spacers. The polyesters prepared were characterized by solution viscosity, differential scanning calorimetry, X-ray diffractometry and polarizing microscopy. All of the polyesters were found to be thermotropic (nematic). Their glass-transition temperatures and mesophase temperature ranges were very sensitive to the length of the two spacers existing in the repeating unit. The degree of branching of one of the polyesters was determined by the NMR spectroscopy and found to be 0.56.
Page
1201 - 1207
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