Novel poly(ether ketone)arylates: Synthesis, characterization and properties

Abstract

In order to reduce the melt temperature (T m ) of the thermotropic crystalline polyarylate and improve its compatibility with poly(ether ether ketone) (PEEK), a series of poly(ether ketone)arylates (PEKARs) containing aryl ether ketone units (AEK) are synthesized through melt transesterification reaction from p-acetoxybenzoic acid, 1,3-bis(4 0 -carboxylphenoxy)benzene and 4,4 0 -bis(pacetoxyphenoxy)benzophenone. The inherent viscosities of these polymers are in the range 0.35-0.81 dL/g. The morphologies and properties of PEKARs are characterized by polarized optical microscopy, wide-angle X-ray diffraction, differential scanning calorimetry, thermal gravimetric analysis, etc. The results show that all PEKARs are semi-crystalline polymers, and the introduction of AEK units can reduce the symmetry of the main chains, leading to decreasing the crystallizability and changing the crystalline form. The PEKARs with AEK less than 30% can exhibit thermotropic liquid crystalline state. The initial and the maximum decomposition temperatures increase with the increase in AEK content. These PEKARs are expected to act as processing agents for PEEK to reduce its processing viscosity.

Effect of thermotropic liquid crystalline poly(ether ketone)arylates on the processibility and properties of poly(ether ether ketone)s fibers

“…The chemical structure of PEKAR used in this study is shown in Figure , which was synthesized from p ‐acetoxy‐benzoic acid, 1,3‐bis(4′‐carboxyphenoxy)benzene, and 4,4′‐bis(3‐hydroxy phenoxy)‐benzophenone with a molar ratio of 70 : 15 : 15. The synthesis procedure was reported in our previous work . The intrinsic viscosity of PEKAR is 0.72 dL/g, and the melting temperature is 319.2°C, but the clear point is not detected below 400°C.…”

New poly(aryl ether ketone)s containing 2,6-diphenylpyridyl units and diphenylphosphinophenyl pendant groups

“…4 Although traditional PEKs such as PEEK and PEKK show excellent performance, their poor solubility in common organic solvents and their high melting temperatures make them difficult to process and fabricate. To overcome these limitations, several approaches have been investigated to improve the solubility and processability of PEKs without significantly weakening their desired properties, such as the introduction of flexible linkages, 5 –7 bulky units, 8 –11 alicyclic moieties, 12 –15 and noncoplanar structures 16 –18 into the main chains of PEKs. Incorporating pendant groups into the PEK backbones is also an effective structural modification method.…”

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

“…Thermotropic liquid crystalline polymers (TLCP) have been attracting an increasing amount of research activities because of their excellent mechanical properties, desired thermal stability, and outstanding chemical resistance, etc . Nowadays, the only industrial product of TLCP is Vectra, which has been co‐developed by Kuraray and Celanese, and synthesized from hydroxybenzoic acid (HBA) and 6‐hydroxy‐2‐naphthoic acid (HNA) with the molar ratio of 73/27 through melt transesterification process (named Vectra A900, and shown in Scheme ).…”

“…This is because Vectra has poor compatibility with PEEK. Our previous works have reported two modification strategies to modify TLCPs for improving the compatibility between PEEK and TLCP . However, the synthesized TLCPs and PEEK are just partially compatible, so they are not highly effective processing agent for PEEK.…”