| Abstract: | The aim of this work is to describe a novel methodology for optimizing the stabilization of polyacrylonitrile (PAN) fibers, through designing of proper thermal treatment. The methodology is based on a set of design rules and the procedure for implementing them, utilizing the time‐temperature‐transition (TTT) and the maximum permittable stress (max.stress) plots. The proposed approach is implemented in order to optimize the stabilization of commercial PAN fibers, resulting in a series of multistage thermal treatments. The changes of both physical and chemical structures of PAN during the progress of the multistage treatments were investigated and showed that the fibers were progressively converted into completely stabilized material; this gradual transformation permitted improvement of fiber annealing and minimized the effect of the decomposition reactions. The proposed methodology can be universally applied for achieving the global optimum of the stabilization process for any PAN precursor. |
