Stabilization Study of Polyacrylonitrile/Cellulose Nanocrystals Composite Fibers

The stabilization process is an important step in converting polyacrylonitrile (PAN) to good mechanical property carbon fiber. Currently, sustainable materials, such as cellulose nanocrystals (CNCs), are gaining attention for conversion to carbon fibers. In this work, the effect of CNCs on the structure, mechanical, and thermal properties of stabilized PAN is systematically studied. In the stabilized PAN/CNC fibers, individual stabilized CNCs were found distributed in stabilized PAN, as observed by elemental composition differences in the two regions. When both the PAN and PAN/CNC composite precursor fibers were processed at a draw ratio of 10x, then the stabilized PAN/CNC fibers exhibited a relatively higher orientation of ladder structure as compared to the stabilized PAN fibers. It was observed that the addition of 40 wt % CNCs into PAN fibers lowers the activation energy of cyclization, and cross-linking but does not change the activation energy of oxidation.