Obtaining and characterization of polyacrylonitrile (PAN) copolymers for use in extruder spinning processes
ABSTRACT The availability of new materials, processes and equipment always brings favorable perspectives to the market. The search for alternative processes and the precursor production cost reduction of high performance materials has become essential for the development of the industrial activity to produce the general purpose carbon fiber to supply the continuously expanding domestic market. The extrusion process of PAN fibers shows potential of cost reduction as it is a precursor of carbon fibers, in relation to the wet spinning method used up to now. This innovative technology enables spinning by melting PAN using glycerin (from biodiesel production) as the primary plasticizer, dispensing the use of highly toxic solvents. Thus, the present work aimed to obtain PAN copolymers that are suitable for the conventional extrusion spinning process. Therefore, PAN copolymer was copolymerized by aqueous suspension and the characterization was performed by Gel Permeation Chromatography (GPC) analysis. The results showed that GPC technique was suitable for determining of the PAN copolymers molecular properties and that styrene monomer was suitable for polymerization, generating PAN-co-ES copolymers with Mn > 40,000 g / mol and Mw > 130,000 g / mol.