A Study Of One-stage Method And Wet-spinning Manufacture Processes Of PAN-based Precursor Using NaSCN As Solvent

The precursor plays a key role in preparation of excellent performance PAN-based carbon fiber. It is fall that manufacture of industrialized scale until now in China. One of the most important reasons is that the quality of the precursor does not pass a barrier really. The reason not only be based on technologies and equipments,and improper management as well as improper decision-making also is an important reason to restrict deep development of carbon fiber.Modification of PAN-based precursor and technological routes and constituents of three co-monomers which were regarded emphases of research by most scholars for improving the quality of precursor. But many present problems,such as impurity content of system, prescription of monomer, various technological conditions and so on, which must be solved in the production of precursor in our country are most important reason.In this paper, the Experimental results of purity of NaSCN solution (13wt %) by membrane separation in Chemical fiber plant of Lanzhou Petrochemical Company and carbide plant are analyzed. The results show that about 80% of impurity in Sodium thiocyanate (NaSCN) solution is removed. It shows that it is completely possibility to find suitable membrane by farther research.The effect of different prescription of acrylonitrile (AN) and methacrylic acid (MA) and itaconic acid (ITA) as co-monomer for primary performance of spinning solution and precursor were studied. The results show that viscidity of PAN solution and content of copolymer and intrinsic viscosity and tensile strength of precursor with prescription (AN∶MA∶ITA=19.0∶0 .93∶0 .23) are the best. The co-monomer content of compound liquid is 5.74%. The impurity content of solvent (52%NaSCN) decrease from 3.5%to 0.89%, the tensile strength of precursor increase 10.2%, it reaches 5.94cN/dtex, unevenness of tensile strength and linear density reaches 27.7% and 37.9%, respectively.