Synthesis Of Thermotropic Liquid Crystalline Copolyester (PET-60HB)and Study Of "In-situ" Composites Consisting Of Poly(ethylene Terephthalate)(PET) And PET-60PHB

In this paper, the thermotropic liquid crystalline copolyester with flexible space group in main chain, PET-6OPHB , was synthesized by using melt-condensation reaction and characterized by JR, polarizing microscope, differential thermal analysis(DTA). melt index measuring instrument, scanning electronic microscope (SEM). The results show that PET-6OPHB copolymers possess typical liquid crystalline property. The blends of PET and PET-6OPHB were prepared by melt blending and characterized by differential scanning calorimetry(DSC), capillary rheometer, melt index measuring instrument, scanning electronic microscope(SEM). The results of experiments indicated that the TLCP phase dispersed well in the PET matrix. There was good interfacial adhesion between PET and TLCP with the addition of the catalyst. The two components of all blends were part-miscible. The rate of crystallization and the crystalhnity of PET were accelerated greatly due to the addition of TLCP in the matrix. The viscosity of all blends was much lower than that of PET, and all blends showed pseudoplastic fluid behavior. The advance of "In-situ"composites consisting of thermoplastic matrix and thermotroptc liquid crystalline polymer was reviewed. According to the miscibility, morphology, rheological property. mechanical property and crystallization property of the blends, It is suggested that the addition of a small amount of TLCP might be a very effective way for developing PET reinforced plastics. Thesen-situomposites reinforced by TLCP will be widely applied to reinforced plastics and fibers ?and predominate over high strength and modulus polymers to substitute for the metals.