Research On Key Technology Of Making High-performance PAN Carbon Fiber Precursors Based On Melt Spinning

Carbon fiber is a kind of special fiber with more than90%carbon. Through the oxidation,carbonization and graphitization process, the carbon fiber has a series of comprehensiveperformance, such as high strength, high modulus, heat resistance, chemical resistance, rubresistance, electric conduction, heat conduction, radioresistance, good damping, shock absorption,noise reduction. Therefore, it is widely used as a composite reinforced material.Precursor level gap is the bottleneck restricting the development of carbon fiber. High qualityof polyacrylonitrile (PAN) precursor is the key to the preparation of high performance carbon fiber,and the weak basic research is the root cause of this situation.In the view of the melt spinning, this paper does the research on the basic problems offorming process, mainly including the rheological properties of PAN spinning solution, thenumerical simulation based on multi-parameters of precursor forming process, the PAN fiberspinning process, and the PAN fiber mechanical properties.This paper firstly analyzes the domestic and foreign research situations and applications ofPAN carbon fiber precursor field; combines the original structure and the spinning process factors;analyzes the key factors which influence the quality of PAN carbon fiber precursors.Secondly, according to the basic control equations of polymer rheology, this paper usesPolyflow software and selects PTT model as the constitutive equation model to do the numericalsimulations on the melt spinning mechanism of PAN. The results show the fluid pressuredistribution and velocity distribution of distributing plate, and the changes of PAN fiber diameter,velocity and temperature curve along the spinning process.Finally, on the basis of numerical calculation, this paper uses appropriate experimentalmaterials and equipments and prepares PAN precursors. In addition, this paper does the tests onthe PAN precursors, including denier measurement, mechanical performance, X-ray diffraction(XRD) and scanning electron microscopy (SEM). Experimental studies show that laboratory PAN precursors has better comprehensive mechanical properties and the strength is higher. But theelongation at break is low and toughness is poor.