Synthesis and characterization of thermotropic liquid crystalline polyarylate with ether ether ketone segments in the main chain

摘要

A series of thermotropic liquid crystalline poly(ether ether ketone) arylates (PEEKARs) were synthesized by combining the synthetic oligomeric poly(ether ether ketone) with terminal acetoxyls (PEEK-A) and oligomeric Polyester with terminal carboxyl (PES-C). The structures of the synthesized monomers and oligomerics were characterized by Fourier transform infrared spectroscopy and H-1 Nuclear magnetic resonance spectroscopy, which indicated that the products were successfully synthesized as designed, and three kinds of PEEKARs with different legend of polyester segments were synthesized. The morphologies and properties of PEEKARs were measured by differential scanning calorimetry, wide-angle X-ray diffraction, thermal gravimetric analysis and polarized optional microscopy. The results show that PEEKAR with the minimum polyester segments has the best crystallization properties, but the flowability of which is rather poor and the liquid crystal character is unobvious; meanwhile, PEEKAR with more polyester segments can form a thermotropic liquid crystal intermediate state, and PEEKAR with maximum polyester segments has a somewhat humble crystallization property; as the content of polyester segments increases, the crystal form of PEEKARs changes and the char yields at 600 degrees C is reduced. (C) 2016 Wiley Periodicals, Inc.