Structural analysis of aromatic liquid crystalline polyesters

4Citations
Citations of this article
6Readers
Mendeley users who have this article in their library.

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. © 2011 by the authors; licensee MDPI, Basel, Switzerland.

Cite

CITATION STYLE

APA

Hall, H., Ahad, S., Bates, R., Bertucci, M., Contreras, C., Dospinoiu, A., … Somogyi, A. (2011). Structural analysis of aromatic liquid crystalline polyesters. Polymers, 3(1), 367–387. https://doi.org/10.3390/polym3010367

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free