Seminar: 9/19/08-Advanced Carbon Fibers for Structural Applications: Role of Molecular Architecture and Nanotexture of Mesogens

Department of Chemical Engineering
West Virginia University

Seminar

Advanced Carbon Fibers for Structural Applications: Role
of Molecular Architecture and Nanotexture of Mesogens


Amod A. Ogale
Department of Chemical Engineering
Clemson University
Clemson, SC


ABSTRACT

Melt-spun polymeric and liquid crystalline precursors are being investigated to develop carbon fibers with controlled microstructure and properties. Discotic liquid crystalline mesophase pitch (MP) precursors result in a high degree of molecular orientation during fiber spinning. The resultant â??radialâ?? texture of the graphene planes leads to carbon fibers with a high graphitic content, high thermal conductivity, and high tensile modulus. However, the tensile strength is not high and the compressive strength is poor. By incorporating carbon nanotubes in an ultradilute concentration (0.1 wt%), we reported a dramatic effect on the resulting nanotexture. A high degree of graphitic crystallinity was retained as observed from a d002 spacing of 0.336 nm, with thermal conductivity predicted at 600 W/m.K. These fibers also possessed a uniform nanotexture that leads to a balance of tensile/compressive properties. The other carbon-fiber precursor, polyacrylonitrile (PAN), is more commonly used in commercial processes. Because of thermal degradation of molten PAN, the precursor fibers have to be spun by a solution route. As an alternative to solvent-based routes, we are developing a UV radiation-based route for processing of melt spinnable PAN. The terpolymers were melt-spun in a suitable processing window, and successfully carbonized following our dual-mechanism of UV-crosslinking and thermo-oxidative stabilization. This environmentally attractive, solvent-free process has the potential to produce high-volume, low-cost carbon fibers for automotive and wind-turbine applications.

Friday, September 19, 2008 9:30am - 10:45am
Room 401, Engineering Sciences Building
Refreshments served at 9:15 am

Questions or Directions call: 304-293-2111, ext. 2418.

09/19/2008