Next Article in Journal
Rotational Diffusion of Macromolecules and Nanoparticles Modeled as Non-Overlapping Bead Arrays in an Effective Medium
Next Article in Special Issue
Polarized Emission of Wholly Aromatic Bio-Based Copolyesters of a Liquid Crystalline Nature
Previous Article in Journal
Surface Modification of Poly(L-lactic acid) Nanofiber with Oligo(D-lactic acid) Bioactive-Peptide Conjugates for Peripheral Nerve Regeneration
Previous Article in Special Issue
Structural Analysis of Aromatic Liquid Crystalline Polyesters
Polymers 2011, 3(2), 833-845; doi:10.3390/polym3020833
Article

Mechanism Studies of LCP Synthesis

 and
*
C.S. Marvel Laboratories, Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA
* Author to whom correspondence should be addressed.
Received: 15 February 2011 / Revised: 24 March 2011 / Accepted: 22 April 2011 / Published: 4 May 2011
(This article belongs to the Special Issue Liquid Crystalline Polymers)
View Full-Text   |   Download PDF [353 KB, uploaded 4 May 2011]   |  

Abstract

The LCP (Liquid Crystal Polymer) known as Vectra is synthesized by acidolysis of 4-hydroxybenzoic acid with 6-hydroxy-2-naphthoic acid. The apparently simple acidolysis mechanism for LCP polycondensation is in fact a complex blend of mechanisms. Kinetics of model reactions and of actual polycondensations followed second-order kinetics and their rate constants were comparable. In the latter stages, ketene loss leads to phenolic ends, while decarboxylation provides phenyl ester ends. Accordingly, the mechanism changes to phenolysis. A quinone methide intermediate may also intervene, as revealed by kinetics studies and MALDI-TOF spectroscopy. Tailor-made matrices and synthesis of alternating well-defined oligomers assisted our studies. Nucleophilic aromatic substitutions may play a role, and we speculate on possible chain polycondensation. Esterolysis may be a useful alternative to LCP synthesis. Complications caused by ketene loss can be averted by the use of methoxycarbonyloxy monomers.
Keywords: Liquid Crystal Polymer; 4-hydroxybenzoic acid; polycondensation; phenolysis; acidolysis Liquid Crystal Polymer; 4-hydroxybenzoic acid; polycondensation; phenolysis; acidolysis
This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).
SciFeed

Share & Cite This Article

Further Mendeley | CiteULike
Export to BibTeX |
EndNote |
RIS
MDPI and ACS Style

Buyle Padias, A.; Hall, Jr., H.K. Mechanism Studies of LCP Synthesis. Polymers 2011, 3, 833-845.

View more citation formats

Related Articles

Article Metrics

For more information on the journal, click here

Comments

[Return to top]
Polymers EISSN 2073-4360 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert