Fabrication of Continuous Fiber-reinforced Thermoplastic Composites with Structural Gradient from Sheath-core Type Bicomponent Fibers

以聚丙烯（PP）或聚碳酸酯（PC）为皮组分，热塑性液晶聚合物（TLCP）为芯组分，采用高速熔融纺丝工艺制备了皮芯型双组分纤维。与PP或PC共处理可以提高TLCP可达到的最高卷绕速度。PP/TLCP和PC/TLCP双组分纤维中TLCP组分的拉伸模量和强度随着卷绕速度的增加而增加。以TLCP为增强纤维，PP或PC为基体聚合物，采用单轴取向双组分纤维模压成型制备了连续纤维增强热塑性复合材料。起始纤维和制造的复合材料的广角X-射线衍射图案的比较表明，TLCP的显着的取向松弛没有发生在压缩成型过程中。相应地，PP/TLCP和PC/TLCP复合材料的拉伸模量和强度分别为 关于我们 E类似于相应双组分纤维的那些。各种类型的复合材料也由双组分纤维制成。通过改变高速熔融纺丝过程中的皮/芯组成，将堆积在筒管上的双组分纤维压缩成型，制备具有结构梯度的复合材料。通过将261根超细纤维嵌入到一根双组分纤维中制备双组分纤维，制备了超细TLCP纤维增强复合材料。采用单向缠绕法制备了双向和三向多层复合材料。正如层合理论所预测的那样，三向增强复合材料在层合平面内表现出各向同性的拉伸模量。由双组分纤维编织纺织品，并通过这些织物的压缩成型制成三向增强复合材料。以这种方式，证明了通过利用高速纺丝的双组分纤维作为起始材料，可以提高连续纤维增强热塑性复合材料设计的灵活性。少

Sheath-core type bicomponent fibers consisting of polypropylene (PP) or polycarbonate (PC) as a sheath component and thermoplastic liquid crystalline polymer (TLCP) as a core component were prepared by the high-speed melt spinning process. The attainable highest take-up velocity of TLCP was improved by co-processing with PP or PC. Tensile modulus and strength of the TLCP component in the PP/TLCP and PC/TLCP bicomponent fibers increased with an increase in the take-up velocity. Continuous fiber reinforced thermoplastic composites, in which TLCP act as a reinforcing fiber and PP or PC as a matrix polymer, were fabricated by the compression molding of uni-axially aligned bicomponent fibers. Comparison of the wide-angle X-ray diffraction patterns of the starting fibers and fabricated composites indicated that the noticeable orientation relaxation of TLCP did not occur in the compression molding process. Accordingly, the tensile modulus and strength of the PP/TLCP and PC/TLCP composites wer … More e similar to those of the respective bicomponent fibers. Various types of composites were also fabricated from bicomponent fibers. Composites having structural gradient was fabricated by compression molding of bicomponent fibers accumulated on a bobbin by changing the sheath/core composition in the high-speed melt spinning process. Composites reinforced with ultra-fine TLCP fibers were fabricated through the preparation of bicomponent fibers in which 261 micro-fibers were embedded in a single bicomponent fiber. Bi-directional and tri-directional multi-layered composites were also prepared using the filament-winding method. As predicted by the lamination theory, composites with tri-directional reinforcement exhibited isotropic tensile modulus in the layered plane. The textile fabrics were woven from the bicomponent fibers and tri-directionally reinforced composites were fabricated by the compression molding of these fabrics. In this manner, it was proved that flexibility in the designing of continuous fiber reinforced thermoplastic composites can be improved by utilizing the high-speed spun bicomponent fibers as a starting material. Less