Chemical Modification for PAN Fibers during Heat-treatment Process

Chemical modification for Polyacrylonitrile (PAN) fibers during heat-treatment process were systematically studied by DSC, FT-IR, EA, XPS, etal. Comparing with original PAN fibers, chemical reactions, structures and elemental compositions of fibers modified with potassium permanganate (KMnO4) solutions were totally changed at a certain extent. KMnO4 had reduced the activation energy of cyclization, decreased the area and widened the peak of exothermic curve, decreased the velocity of cyclization reaction, increased the oxygen content about 67%, hence increased C-O-C and C=O groups and the core/shell ratio.