Research On Preparation Of Polymer Liquid Crystal And Its Blood Compatibility

For the purpose of research on relationship between liquid crystal phenomena and blood compatibility, the propionic, n-butyric esters of hydroxypropyl cellulose(referred to as PPC, BPC) were prepared with hydroxypropyl cellulose(HPC) and propionyl chloride/ butyryl chloride. The reaction conditions and phase behavior have been studied. The results show that the reaction time, temperature and amount of propionyl (or butyryl) chloride have effect on content of propionyl(or butyryl), and the amount of proionyl chloride(or butyryl chloride)is more obvious than the other factors. The DSC result and the observation of polarizing microscope indicate that PPC and BPC are thermotropic polymer liquid crystals exhibiting cholesteric reflection color at room temperature. Then PPC/PU and BPC/PU membranes were prepared with the use of polyurethane(PU). The mechanic properties and blood compatibility of these two membranes have been tested. It is indicated that the strength of PU is weakened and the elongation is reduced because of the addition of the polymer liquid crystals. However, the PPC and BPC have improved the blood compatibility of PU. It concludes that the liquid crystal structure has good effect on improvement of blood compatibility of materials such as PU.