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Wholly aromatic polyesters derived from 6‐hydroxy‐5‐phenyl‐2‐naphthoic acid and 4'‐hydroxy‐3′ ‐phenylbiphenyl‐4‐carboxylic acid
Author(s) -
Jin JungIl,
Huh SeungMoo
Publication year - 1995
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19950960110
Subject(s) - thermotropic crystal , polyester , differential scanning calorimetry , crystallinity , phenylene , carboxylic acid , thermogravimetry , polymer chemistry , moiety , monomer , thermal stability , materials science , condensation polymer , naphthalene , liquid crystal , organic chemistry , crystallography , chemistry , polymer , liquid crystalline , physics , optoelectronics , thermodynamics , inorganic chemistry
Two series of new wholly aromatic copolyesters were prepared from 6‐hydroxy‐5‐phenyl‐2‐naphthoic acid (HPNA) and 4‐hydroxybenzoic acid (HBA), and 4'‐hydroxy‐3'‐phenylbiphenyl‐4‐carboxylic acid (HPBA) and 4‐hydroxybenzoic acid in varying mole ratio. The polyesters were synthesized in melts using the acetylated monomers. They were characterized for their crystallinity, liquid crystallinity, thermal transitions and thermal stability by wide‐angle X‐ray diffractometry, differential scanning calorimetry, thermogravimetry and on a polarizing microscope. In general, the HPNA copolyesters revealed higher degree of crystal‐Unities and greater melting temperatures than the HPBA copolyesters. This difference is explained by the planar geometry of naphthalene moiety in the HPNA structure. In contrast, the two phenylene rings of the HPBA unit along the backbone may not be coplanar. All of the polyesters appear to be thermotropic.