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Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 21, Number 9
BKCSDE 21(9)
September 20, 2000 

 
Title
Synthesis and Characterization of Poly(arylene ether)s Containing Benzoxazole pendants from Novel Aromatic Dif-luoride Monomer
Author
Ji-Heung Kim,* Sang Woo Bang, Young Jun Kim
Keywords
Abstract
A study was done on the synthesis of new poly(arylene ether)s and poly(arylenesulfide) with rigid benzoxazole pendants using nucleophilic aromatic substitution reaction. As a new aromatic monomer, 1,4-bis(2-benzox-azolyl)-2,5-difluorobenzene [I] was synthesized in three steps starting from 1,4-dibromo-2,5-difluorobenzene. A model reaction of difluoro monomer [I] with two equivalents of m-cresol or thiophenol in a typical ether con-densation reaction conditions gave very high yields ( > 93%) of the desired disubstituted product, suggesting the feasibility of polymer formation in these reaction system. Monomer[I] was polymerized with bisphenols and bisbenzenethiol in NMP using K2CO3 as base. The molecular weight of the resulting polymers, however,seemed relatively low according to their solution viscosity values ( ηinh = 0.15-0.29 dL/g). The poly(arylene ether)s were soluble in several common organic solvents including chloroform, pyridine and N,N'-dimethylfor-mamide. The poly(arylene sulfide) was, however, ony soluble in strong acids like sulfuric acid and trifluoro-acetic acid. The glass transition temperatures were found to be 175-215 ℃. These polymers were stable up to 380-420 ℃ in both nitrogen and air, as determined by the temperature that a significant weight loss began to appear on TGA.
Page
896 - 900
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