Influence of Melt Temperature on Structure of Polyacrylonitrile in Ionic Liquids during Plasticized Melt Spinning Process

The carbon fiber has excellent properties; however, the high cost limited its wide application. Here we report a novel process to reduce the heat emission during stabilization by in situ modification of spinning melt. In this paper, the effect of extruding temperature on the structures of PAN in the PAN/ILs melt was investigated by twin-screw extruder. FTIR and UV-vis absorption spectra of modified samples showed the formation of C=C and C=N group, which indicated the occurrence of cyclization and dehydrogenation reactions of PAN during extrusion process. The degree of cyclization was calculated from DSC test and the degree of cyclization can be up to 24.5% with the residence time of 14 min at 210 oC, which could decrease the heat release in the subsequent stabilization process during carbon fiber production. Therefore, this method should be benefit to improve the processing efficiency during stabilization process.