Processing and performance of aromatic-aliphatic thermotropic polyesters based on vanillic acid

Carolus H. R. M. Wilsens, Yogesh S. Deshmukh, Wenqing Liu, Bart A. J. Noordover, Yefeng Yao, Han E. H. Meijer, Sanjay Rastogi*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

In this work we report on the processing, melt-drawing, and performance of new vanillic acid based aliphatic-aromatic thermotropic polyesters. It is demonstrated that these materials are easily processed from their nematic melts yielding highly oriented products. Furthermore, we demonstrate that a molecular weight (M-w) of roughly 30 kg/mol is required in order to successfully perform spinning on these polymers. The application of a polymer with lower M-w results in poor mechanical performance and fiber breakage during the winding process. Wide-angle X-ray diffraction analysis has been performed on the fibers and it is demonstrated that the orientation parameter increases with increasing draw-ratio of the fiber. Although these polymers are readily processed from their thermotropic melts, the obtained fibers only retain their orientation up to temperatures in the range of 120-130 degrees C, after which they start to melt. In general, these fibers exhibit tensile moduli in the range of similar to 10 GPa and a tensile strength around similar to 150-200 MPa. FTIR and solid-state NMR experiments indicate that only the aromatic components are molecularly oriented during the spinning process. In contrast, the aliphatic moieties exhibit a high mobility, normally corresponding to a local isotropic motion. It is expected that the poor molecular orientation of the aliphatic moieties in these aliphatic-aromatic thermotropic polyesters contribute to the relatively low tensile modulus of the fibers, obtained after the extrusion and melt-drawing process.
Original languageEnglish
Pages (from-to)198-206
JournalPolymer
Volume60
DOIs
Publication statusPublished - 9 Mar 2015

Keywords

  • Fiber
  • Thermotropic melt
  • Vanillic acid

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