Research On The Oxidation Of Pan Tow

The modified flame-retardant polyacrylonitrile(PAN) tow were prepared with CuCl at the conditions of uncontinous and continuous oxididation.We discussed the effect of chemical modification on thermal reation and mechanical properties of the PAN tow. The structure and properties of untreated and treated PAN precursors were characterized by IR, DSC, SEM, X-ray diffraction and other analysis, and the paper made a preliminary discussion on the effect of cuprous chloride modification on PAN precursors.It was suggested that PAN precursors pretreated with CuCl can enhance the rate of cyclization, accelerate the formation of ladder structure.Also it can achieve better oriented as well as a more crystalline structure. It shows that CuCl modification can lower the temperature of cyclization reaction, reduce the time required for stabilization. At the same time the resulting oxidized fibers achieved an elongation of17.6%for the temperature range of exothermic process,and an improvement in tensile strength of46%.Moreover, the effect of draw-ratio on the structure and properties of PAN precursors were discussed on condition that other processing parameters (i.e., modification time, modification temperature, oxidized temperature etc.) were kept constant.The results indicated that as the draw ratio increased, both the mechanical properties and the orientation degree of PAN precursor has been improved.It should be noted that the optimal draw ratio is4%.