Processing and performance of aromatic-aliphatic thermotropic polyesters based on vanillic acid. (9th March 2015)

• Record Type: Journal Article
• Authors: Wilsens, Carolus H.R.M.; Deshmukh, Yogesh S.; Liu, Wenqing; Noordover, Bart A.J.; Yao, Yefeng; Meijer, Han E.H.; Rastogi, Sanjay
• Is Part Of: Polymer. Volume 60(2015)
• Page Start: 198
• Page End: 206
• Publication Date: 2015-03-09
• Subjects: Fiber -- Thermotropic melt -- Vanillic acid; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2015.01.045
• Languages: English
• ISSNs: 0032-3861

Abstract

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 °C, after which they start to melt. In general, these fibers exhibit tensile moduli in the range of ∼10 GPa and a tensile strength around ∼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. Graphical abstract: Highlights: Bio-based aliphatic-aromatic thermotropic polyesters. Vanillic acid based polymers. Fiber spinning, solution casting, compression molding.