Polymers 2011, 3(1), 367-387; doi:10.3390/polym3010367
Article

Structural Analysis of Aromatic Liquid Crystalline Polyesters

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Received: 21 December 2010; in revised form: 13 January 2011 / Accepted: 20 January 2011 / Published: 27 January 2011
(This article belongs to the Special Issue Liquid Crystalline Polymers)
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.
Abstract: Laboratory preparations of liquid crystalline prepolymers, distillates accompanying prepolymers, final polymers, and sublimates accompanying final polymers were examined. NaOD/D2O depolymerization of prepolymers and polymers back to monomers with integration of the 1H NMR spectra showed up to 6% excess of carboxyls over phenol groups, caused partly by loss of the low-boiling comonomer hydroquinone through distillation during prepolymerization and leaving anhydride units in the polymer chain. ESI MS and MS/MS of hexafluoroisopropanol extracts of the prepolymer detected small molecules including some containing anhydride groups; ESI+ MS showed the presence of small cyclic oligomers. 1H NMR (including TOCSY) spectra provided more quantitative analyses of these oligomers. The final polymerization increases the length of the polymer chains and sublimes out the small oligomers. Anhydride linkages remaining in the polymer must make LCP’s more susceptible to degradation by nucleophilic reagents such as water, alkalis, and amines.
Keywords: copolymerization; LCP’s; mass spectrometry; NMR; polyesters
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MDPI and ACS Style

Hall, H.; Ahad, S.; Bates, R.; Bertucci, M.; Contreras, C.; Dospinoiu, A.; Lin, G.; Singletary, N.; Somogyi, A. Structural Analysis of Aromatic Liquid Crystalline Polyesters. Polymers 2011, 3, 367-387.

AMA Style

Hall H, Ahad S, Bates R, Bertucci M, Contreras C, Dospinoiu A, Lin G, Singletary N, Somogyi A. Structural Analysis of Aromatic Liquid Crystalline Polyesters. Polymers. 2011; 3(1):367-387.

Chicago/Turabian Style

Hall, Henry; Ahad, Samiul; Bates, Robert; Bertucci, Maria; Contreras, Cristina; Dospinoiu, Alexandru; Lin, Guangxin; Singletary, Nancy; Somogyi, Arpad. 2011. "Structural Analysis of Aromatic Liquid Crystalline Polyesters." Polymers 3, no. 1: 367-387.


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