Cellulosic Carbon Fiber Precursors from Ionic Liquid SolutionsEPA Grant Number: R831658
Title: Cellulosic Carbon Fiber Precursors from Ionic Liquid Solutions
Investigators: Collier, John R. , Petrovan, Simioan , Rials, Timothy G.
Institution: University of Tennessee - Knoxville
EPA Project Officer: Carleton, James N
Project Period: June 1, 2004 through May 31, 2007 (Extended to May 31, 2008)
Project Amount: $350,000
RFA: Technology for a Sustainable Environment (2003) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , Sustainability
The central objective of this work is to develop a better understanding of the relationship between the morphology of cellulose fibers spun from an ionic liquid and the properties of carbon fibers produced from these cellulose fibers. There are three innovations involved in this project. First, developing an understanding of the interactions of the ionic liquid with low-cost cellulose isolated with relatively high amounts of impurities, hemicelluloses and lignin. The second innovation is the use of an elongational flow spinning process that reduces swell and relaxation and induces highly oriented and highly crystalline cellulosic precursor fibers that can be converted to higher quality carbon fibers. The third innovation involves improvements in the carbonization process, including the use of new catalysts that will increase the carbon fiber yield and quality. This should form the foundation for a new generation of low-cost carbon fibers.
To facilitate a clear fundamental understanding of the interactions between the cellulose source and the effects of secondary cellulose components, and the fiber spinning and carbonization, two well-defined sources of cellulose will be used. The celluloses will be mixed with well-defined hemicellulose and lignin to create model systems for the low-cost cellulose feed stocks. Solution rheology and chemical interactions determined by FTIR between the different polymeric components and the ionic liquid will be studied. Subsequently monofilament fibers will be spun form the cellulose and from the mixed cellulose solution in the ionic liquid and the key variables determined. Carbonization will be studied on similar fibers for which catalytic acting salts and acids have been added to the ionic liquid solutions of cellulose and mixed cellulose. Subsequent to the carbonization, pyrolysis molecular beam spectroscopy, x-ray analysis and mechanical properties will be used to analysis the characteristics of the final carbon fibers.
It is anticipated that this research will result in enhanced lower cost carbon fibers produced from what is now considered to be agricultural residues and using a process that is significantly more environmentally friendly that current processes. The carbon fibers produced will probably not have as high a modulus or tensile strength as the best currently available carbon fibers but should be sufficiently strong and less expensive to be cost effective for use in vehicular applications.
Estimated Improvement in Risk Assessment or Risk Management: The use of elongational flow spinning techniques that produce highly oriented cellulose fibers and a novel cellulose solvent that has no emissions will reduce the environmental footprint and costs of carbon fibers. Furthermore, the availability of lower cost yet sufficient, strong carbon fibers will enable the fabrication of lighter composites for vehicular applications resulting in lower fuel consumption and related emissions.