| 초록 |
Poly(p-phenylene benzobisoxazole) (PBO) has been known as a rigid-rod polymer with high tensile strength and thermal stability. But, it has relatively weak compressive strength. In this work, we have prepared a series of PBOs containing trifunctional moiety in their backbones by the copolymerization of 4,6-diaminoresorcinol dihydrochloride (DAR) with terephthaloyl chloride (TPC) and 1,3,5-benzenetricarbonyl trichloride (BCT) in poly(phosphoric acid). The content of BCT in the copolymerization is adjusted to be 0.0~1.0 mol% of TPC. Accordingly, molecular weights and structures of the PBOs with different BCT contents are characterized by using solution viscometry, FT-IR spectrometry, and polarized optical microscopy. In addition, PBO fibers are prepared by in-situ dry-jet wet-spinning of the reaction products. The effects of BCT content on the thermal stability, tensile mechanical properties, and compressive strength of the PBO fibers are investigated by using TGA, DSC, and UTM. |
