Experimental Utah Coal Tar Pitch - Based Carbon Fiber

Scope of Work The University of Kentucky, through a group led by Dr. Matthew Weisenberger, has been engaged in research on carbon fiber production for over 15 years. They have established a state-of-the-art carbon fiber production laboratory that includes a wide range of test equipment for characterizing important physical properties of the finished carbon fiber. The University of Utah has been collaborating with the University of Kentucky on the production of carbon fiber from coal-derived pitch for the past two years. As part of the effort to scale-up the production of pitch derived from Utah coals, it is important that we continue the collaboration between the University of Kentucky (UKY) and the University of Utah (UUT). UKY has a wealth of experience to characterize pitch, melt spin (and filter) pitch into green fiber, thermally convert the green fiber into carbon fiber, and characterize the fiber – all from a coal derived pitch. Thus, this scope of work describes the work UKY will do to support the efforts described in UUT Tasks 1- 2. The essence of this scope of work is for producing carbon fiber from Utah pitch with at least 50% mesophase. The work provided by the University of Kentucky will include: 1. Softening point evaluation of the UUT pitch by dynamic mechanical analysis (DMA) 2. Melt spinning of the raw mesophase pitch provided by UUT into green fibers, with specific efforts to: a. Determine ways to reduce the green fiber diameters to an appropriate diameter for industry use; b. Identify ways to mitigate voids in the final fibers c. Identify trade-offs between temperature, viscosity and shear rate on the ‘spinnability’ of the Utah coal pitch material. 3. The green fibers will be further processed through oxidation, carbonization and graphitization steps to produce a final carbon fiber. 4. The carbon fiber product will be analyzed for physical properties such as tensile strength and modulus, and will be also be imaged using scanning electron microscopy (SEM) to identify the presence of favorable microstructure. As part of accomplishing the proposed scope of work, funds for the acquisition of a capillary rheometer are requested. The capillary rheometer is uniquely critical for this work in that it specifically allows for the melt rheology and spinning of very small batches of pitch – as UUT envisions producing – for experimental validation of the overall concept. Specifically, it enables the melt extrusion of batches as small as 7 grams of pitch. Moreover, it imparts a high precision volumetric flow rate of the molten pitch out of the capillary die, which is vital for stable melt spinning. This acquisition is wholly supports Task 2 above, and particularly Task 2c. UKY will modify the capillary rheometer system with its specialized equipment for in-situ melt filtering, custom capillary dies, and a custom wind-up system for the melt spinning. The green fibers will then be processed into carbon fiber and characterized per Task 3 and 4. This information on the final carbon product will then be related to the pitch processing conditions used by the University of Utah, to identify key relationships that can affect product quality.