BIMODIFICATION OF POLYACRYLONITRILE (PAN) FIBERS

A new technique for the modification of PAN fibers has evolved, in whi ch the starting precursor material is impregnated with an aliphatic ca rboxylic acid, as well as KMnO4. The bimodification of PAN, attempted by us for the first time, is aimed at achieving dual advantages in pla sticization effect, as well as in a catalytic effect in a single treat ment. The unmodified, unimodified, and bimodified precursors have been characterized for their mechanical, thermal, and physical behavior du ring various stages of processing to carbon fibers. These results are discussed in detail. The study further shows an 18% improvement in the mechanical properties of carbon fibers, prepared from bimodified prec ursor, as compared to that of unmodified precursor. One of the reasons for such improvement is the lowering in diameter of PAN fibers and in the resulting carbon fibers.