Mechanical Properties of PAN-based Carbon fiber According to Comonomer Feed Time

Abstract

In Polyacrylonitrile (PAN)-based carbon fiber manufacturing process, the mechanical properties of carbon fibers are strongly influenced by the stage of polymer synthesis. For a polymer of the same mass, the larger the molecular weight, the fewer the chain ends. In the microstructure of carbon fibers, the chain ends of PAN polymers act as defects in the carbonization process of the fiber, which reduces the mechanical properties of the carbon fiber. It is well known that PAN polymer molecular weight is affected by the comonomer feed time. In this research, we describe how the variation of PAN polymer molecular weight with comonomer (methacrylic acid) feed time affects the mechanical properties of carbon fibers. The PAN precursor fibers (P(AN-MAA) copolymers) were stabilized and carbonized through continuous heat treatment. For the high-performance carbon fibers manufacturing process, the correlation between the comonomer feed time and the mechanical properties of the carbon fiber was analyzed using tensile tests and wide-angle X-ray diffraction.