Title: CONTROLLING SEMI-CRYSTALLINE MORPHOLOGIES OF CARBON FIBER COPOLYMER PRECURSORS BASED ON POLYACRYLONITRILE
Abstract: We investigated the effect of semi-crystalline morphologies from Polyacrylonitrile (PAN) copolymer carbon fiber precursors on exotherm. Our principle hypothesis was that controlling the semi-crystalline morphologies in PAN copolymers will provide new routes to control exotherm and ultimate properties in carbon fiber. Copolymers with new acrylamide comonomers were polymerized via Free Radical, Batch RAFT and Semi-Batch RAFT. Proton NMR and SEC confirmed that well-defined copolymers with new comonomers for PAN based carbon fiber were successfully synthesized. All copolymers were found to have a lower exotherm peak temperature and increased exotherm breadth than homopolymer PAN. Semi-Batch RAFT copolymers cyclized at earlier temperatures than their respective Free Radical copolymers which indicated polymerization mechanism had an effect on cyclization mechanism. All NEAA copolymers gave lower exotherm temperatures than NTAA copolymers. This indicated that NEAA copolymers will cyclize at earlier temperatures leading to a greater cyclized final graphitic structure than NTAA copolymers.
Authors: Katelyn J. Cordell, Roger J. Dias, Christian R. Dias, Jeffrey S. Wiggins
Conference: CAMX 2017 –Orlando