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Polymers 2011, 3(2), 833-845; doi:10.3390/polym3020833
Article

Mechanism Studies of LCP Synthesis

 and *
Received: 15 February 2011; in revised form: 24 March 2011 / Accepted: 22 April 2011 / Published: 4 May 2011
(This article belongs to the Special Issue Liquid Crystalline Polymers)
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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 which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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MDPI and ACS Style

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

AMA Style

Buyle Padias A, Hall, Jr. HK. Mechanism Studies of LCP Synthesis. Polymers. 2011; 3(2):833-845.

Chicago/Turabian Style

Buyle Padias, Anne; Hall, Jr., Henry K. 2011. "Mechanism Studies of LCP Synthesis." Polymers 3, no. 2: 833-845.


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