Melt spinning of poly(acrylonitrile)-co-styrene copolymer

Abstract

The search for alternative processes and high performance materials precursors for carbon fibers, has been continuously the aim for use in the aerospace, automotive, energy and sports goods market. The reduction in the precursor production cost is then essential to allow the installation of an industrial plant to produce a general purpose carbon fiber. Polyacrylonitrile has been the main precursor for carbon fiber production. It has been produced by the wet and dry spinning process since it has been discovered in the beginning of the forties. Nowadays, the extrusion process of PAN fibers shows potential of cost reduction in relation to the wet spinning method. This innovative technology enables spinning by melting PAN polymer by using glycerin as the primary plasticizer, avoiding the use of highly toxic solvents. In the present work, PAN copolymer was copolymerized by conventional aqueous suspension. Its characterization was performed by FT-IR, GPC and DSC analysis. The fibers obtained by extrusion process were characterized by SEM, DSC/TGA analysis and kinetics of the thermal stabilization process was studied by Kissinger method. The results showed that styrene monomer was suitable for polymerization with PAN leading to a molecular weight Mn= 46,000 g/mol and Mw = 138,000 g/mol. The PAN-co-Styrene copolymer was suitable for obtaining extruded PAN fibers continuously with morphological and thermal properties having properties similar to commercial PAN fibers.