THE SYNTHESIS AND CHARACTERIZATION OF NOVEL THERMOTROPIC LIQUID-CRYSTALLINE POLY(ARYL ETHER KETONE)S

Citation
Gs. Bennett et Rj. Farris, THE SYNTHESIS AND CHARACTERIZATION OF NOVEL THERMOTROPIC LIQUID-CRYSTALLINE POLY(ARYL ETHER KETONE)S, Polymer engineering and science, 34(10), 1994, pp. 781-793
Citations number
25
Categorie Soggetti
Polymer Sciences","Engineering, Chemical
ISSN journal
00323888
Volume
34
Issue
10
Year of publication
1994
Pages
781 - 793
Database
ISI
SICI code
0032-3888(1994)34:10<781:TSACON>2.0.ZU;2-K
Abstract
The synthesis and characterization of novel thermotropic liquid crysta lline poly(aryl ether ketone)s based on the reaction of a liquid cryst alline mesogen containing monomer, biphenol, and a crystal-disrupting substituted monomer, t-butyl- or phenyl-, hydroquinone with 4,4'-diflu orobenzophenone are described. Two families of copolymers-a biphenol/t -butylhydroquinone series of 90, 75, 50, 25, and 0% biphenol, and a bi phenol/phenylhydroquinone series of 75, 50, 25, and 0%-are evaluated. Thermotropic liquid crystalline behavior was observed in the copolymer s containing 50 and 75% biphenol. The first order and second order tra nsitions associated with melting, crystallization, thermotropic liquid crystalline mesophases, and glass transition temperatures (Tgs) of ea ch copolymer are investigated. The thermal transitions are correlated with optical microscopy and X-ray and/or electron diffraction characte ristics. It was observed that the Tg increases and end group concentra tion decreased after isothermal heat treatment indicative of further p olymerization. These materials are believed to be the first known ther motropic liquid crystalline poly(aryl ether ketone)s.