초록
The correlation between the imidization degree of polyimide fibers and characteristics of activated carbon fibers was studied. Poly(amic acid) solution was spun by dry-jet wet spinning method and poly(amic acid) fibers were transferred into polyimide fibers by heat treatment of IR heater at 300 ℃, 400 ℃, 500 ℃, 600 ℃. Polyimide fibers were carbonized and activated at 900 ℃. The imidization degree was investigated using FT-IR. The chemical structure was traced by FT-IR, elemental analyzer(EA) and x-ray diffraction(XRD). Thermal properties were analyzed with DSC and TGA. Mechanical properties were measured with single fiber tester(favimat). Specific surface area and pore characteristics were analyzed by BET method. The surface morphologies were observed by FE-SEM. The imidization degree of polyimide fibers increased up to 500 ℃ but decreased at 600 ℃. The thermal and mechanical properties of polyimide fiber exhibited a dependency on the imidization degree. The mechanical properties and compact morphologies of activated carbon fiber strongly depended on the imidization degree of polyimide fiber. Activated carbon fiber was showed the maximum tensile strength value of 898 MPa and specific surface area composed of micropores value of 920 ℃/g at IR heater temperature of 500 ℃ and the imidization degree of 96%.