Synthesis and Characterization of Highly Soluble Fluorinated Polybenzoxazoles by Direct polycondensation

摘要

@@Aromatic polybenzoxazoles (PBO) are a class of aromatic heterocyclic polymers that have excellent thermal stability, high mechanical properties, and good chemical resistance. The excellent thermal stability and high flame resistance of PBO make it the material of choice for high-temperature applications. However,analogous to aromatic polyimides, they are generally difficult to process because of their poor solubility in organic solvents. Consequently, versatile applications are limited. Thus, to allow for easier processing and fabricating, it is imperative that the solubility in common solvents be increased. On the other hand,fluorine-containing polymers have been synthesized and developed as high-performance polymers with unique chemical and physical properties that are not observed with other organic polymers. They possess improved thermal stability, high chemical stability, low refractive index and etc. It was expected that the introduction of bulky trifluoromethyl groups can inhibit efficiently the PBOs to form regular chain structure and increase the molecular polarity correspondingly. Furthermore, the existence of aromatic C-F bond was expected to enhance the thermal stability of the polymers. Therefore, the resulting PBOs may exhibits a good solubility in organic solvents without sacrificing the above excellent properties.