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The Influence of Thermal Annealing on Microstructure and Mechanical Properties in High Performance Liquid Crystal Copolyesters

Published online by Cambridge University Press:  16 February 2012

Adriana Reyes-Mayer
Affiliation:
Laboratorio de Nanopolimeros y Coloides, Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Cuernavaca, Mor. 62210, MEXICO. Facultad de Ciencias, Universidad Autonoma del Estado de México, Instituto Literario #100, Toluca, Edo de Mexico, C.P. 50000, MEXICO.
Amaury Constant
Affiliation:
Faculte des Sciences d’Orsay, Universite Paris Sud XI, Orsay, Cedex, FRANCE.
Angel Romo-Uribe*
Affiliation:
Laboratorio de Nanopolimeros y Coloides, Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Cuernavaca, Mor. 62210, MEXICO.
Michael Jaffe
Affiliation:
New Jersey Institute of Technology, Newark NJ, U.S.A.
*
*Contact author: [email protected]
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Abstract

In this research we have focused on the influence of thermal treatment for periods of time on the thermal and mechanical properties of extruded films of a series of high-performance thermotropic liquid crystal polymers (LCPs). The dependence of microstructure, thermal and mechanical properties on the extent of thermal treatment is investigated. Especially synthesized wholly aromatic LCPs based on hydroxybenzoic acid (B), hydroxynaphthoic acid (N), terephthalic acid (TA) and biphenol (BP) are kindly supplied by Hoechst Celanese Research Corp in the form of 50 μm thick extruded films. Thus, the influence of monomer composition is also studied in order to contrast the influence of molecular conformation. Thermal treatments are carried out at temperatures close to the solid-to-nematic transition (Ts→n) for up to several hours under dry air conditions. The results show a profound influence of thermal annealing on morphology and mechanical modulus when annealing is carried out c.a. 40ºC below Ts→n, where solid-to-nematic transition and Young’s modulus are significantly increased.

Type
Articles
Copyright
Copyright © Materials Research Society 2012

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References

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