1997 Volume 9 Issue 11 Pages 920-926
Sheath-core type bicomponent fibers consisting of poly (ethylene terephthalate) (PET) as a sheath component and thermotropic liquid crystalline polymer (LCP) as a core component were prepared by a high-speed melt spinning process, and continuous fiber-reinforced thermoplastic composites were fabricated from these fibers. The processability of LCP was improved by co-processing with PET, and tensile modulus and strength of the LCP component in the PET/LCP bicomponent fibers were enhanced in comparison with LCP single component spinning. Wide-angle X-ray diffraction patterns showed that the molecular orientation of LCP component in thermoplastic composites did not change as compared to those in the as-spun bicomponent fibers. The tensile modulus and strength of PET/LCP bicomponent fibers and thermoplastic composites were also similar. To combine the fiber spinning process with the thermoplastic composites processing, thermoplastic composites with a structural gradient in fiber content were also fabricated from the bicomponent fibers in which sheath-core composition was continuously changed during the spinning process. In the three-point bending test of these composites, different mechanical behavior, depending on load direction, appeared. This behavior of the composites prepared in our study is similar to that of bamboo which has a very similar structure.
