SELF-REINFORCED COMPOSITES OF VARIOUS POLYESTERS WITH PET/HBA BASED LCP

摘要

Four different polyesters, PET, PBT, PEN, and copolyester, were each blended with LCP based on poly(ethylene terephthalate)/p-hydroxybenzoic acid, PET/HBA, by using a single screw extruder with a static mixer followed by a die. Unidirectional sheets and fibers of the blends of various LCP contents were prepared at various operating conditions including die geometry, die temperature, and extension ratio to find optimum processing conditions required for improvement of mechanical properties. Depending on matrix and processing conditions, blends revealed different LCP domain deformation, size, shape, and, consequently, mechanical properties. Among four different polyesters, PET matrix was the most efficient in obtaining uniform LCP phase distribution and deformation in blends. However, blends based on the copolyester matrix showed the best mechanical properties. The mechanical properties of injection moldings made by reprocessing thermoplastic/LCP fibers at the melt temperature below the LCP melting point were measured. Among various blends, the LCP fibrils preexisting in PEN/LCP fibers were best preserved in moldings.