Effects of novel thermotropic liquid crystalline polyester with aryl-ether linkages on the processability and properties of poly(ether ether ketone)s fibers

A series of composite fibers based on poly(ether ether ketone)s (PEEK) and a novel thermotropic liquid crystalline polyetherarylates (PEAR) with the aryl-ether linkages, have been prepared by melt spinning. The impact of PEAR on PEEK is investigated by rheological measurements, differential scanning calorimetry, thermal gravimetric analysis, wide angle X-ray diffraction and scanning electron microscope, orientation degree test and mechanical properties test, etc. The results show that the flowing curves of the blends can be divided into three regions: the first shear thinning region, the shear thickening region, and the second shear thinning region; meanwhile, the PEAR can function as a processing aid by reducing the viscosity of PEEK, thus the processing can be carried out at relatively low temperatures. Although, they are partially compatible, the mechanical properties of the post-treatment fibers have been improved by 14% after adding 2% PEAR to PEEK. The crystallinity of the as-spun fibers increases from 22.47 to 42.10%, suggesting that PEAR can act as nucleating agent. Regretfully, both of the initial degradation temperatures and the maximal degradation temperatures decrease with the increase of the PEAR content. © 2012 Wiley Periodicals, Inc.