Recipient: 2008 National Women of Color Technology Award
Over her 17-year career with the National Aeronautics and Space Administration (NASA), Dr. Chun-Hua “Kathy” Chuang has had a significant impact on the aerospace industry and materials community through her novel research on improving the processability, performance and stability of high-temperature polymers and fiber-reinforced composites. In addition, she has demonstrated a commitment to professional growth through her active involvement in technical societies and her frequent participation in technical society meetings and workshops on advanced materials. Dr. Chuang has also shared her talents and expertise with others through the mentoring of student interns and her interactions with faculty and students at minority serving institutions.
Dr. Chuang has been a pioneer in the development of processable high-temperature polymers and composites for aerospace propulsion applications. Use of fiber-reinforced polymer matrix composites as replacements for metal in aerospace components can lead to weight reductions on the order of 30%. This weight savings translates into increased fuel economy and reduced emissions, increased payload or passenger capacity, and improved range or operability. More extensive use of composites, in particular high-temperature materials, in aircraft and spacecraft is hampered by high manufacturing costs and the inherently poor high-temperature stability relative to that of other aerospace materials.
Addressing these two issues is a highly complex problem because changes in the chemical structure of the polymer that would impart good processability have an adverse effect on high-temperature properties and stability. Dr. Chuang’s innovative research has been able to tread that fine line between improved processability, properties and stability. In addition to her contributions to fundamental aspects of high-temperature polymers and composites, she has also been highly successful in transferring the technology she has developed to industry.
In a co-funded collaboration with the Naval Warfare Center, she addressed the issue of the poor durability of composites used in missile applications through a combination of new high-temperature polymers and novel reinforcement architectures. This work led to the development off the first polymer matrix composite to survive exposures to 1000°F under extremely high heating rates. Previous work with composites had shown that upon exposure to extreme temperatures and high heating rates, conventional composites undergo catastrophic delamination due to the rapid loss of volatile materials from the interior of the composite. Dr. Chuang demonstrated that 3-D reinforcement of composite materials eliminates this delamination.
In order to provide for a matrix resin with the high-temperature capabilities required for this application, she developed DMBz-15, the first processable, high-temperature polymer capable of use at temperatures up to 650°F. This invention utilized a novel “twisted” biphenyl diamine structure to impart high-temperature performance to the polymer while still maintaining good processability. DMBz-15 was the recipient of the prestigious R&D-100 Award in 2003. In addition, Dr. Chuang received a NASA Space Act Award for this polymer, which recognizes NASA-developed technologies that have significant impact on NASA missions and programs.
In another joint project with industry, she developed an ultrahigh temperature polyimide, HFPE, which can be processed by both conventional methods and by resin film infusion, a more cost effective processing technique. Under a cost-shared program with NASA Glenn Research Center, Boeing evaluated the processing and performance of this polymer against other resins that they examined dating back to the High Speed Research Program in the 1990’s and found it to have the best retention of mechanical properties at high temperatures of any resin that they have tested. The Boeing Corporation is evaluating this composite for use in both commercial and military aircraft applications.
More recently, she has turned her attention to the development of high-temperature resisistant polymers that can be processed by cost-effective methods, such as resin transfer molding and resin film infusion. These methods require resins with melt viscosities no higher than 6000 centiPoise, about 100 times lower than that of conventional high-temperature polymers. Reducing the melt viscosity of the polymer, while still preserving high-temperature performance is particularly challenging because those chemical structures that impart low melt viscosity tend to reduce high-temperature stability and performance.
In collaboration with Clark Atlanta University, Atlanta, GA and M&P Technologies, a small business also in Atlanta, GA, she has developed new polymers that can be processed by resin transfer molding. These new resins have mechanical properties at high temperatures (up to 600°F) that exceed those of any RTM processable resin, commercially available or experimental. Dr. Chuang and her collaborators at Clark Atlanta University were successful in obtaining funding from the Air Force Office of Scientific Research to further develop these resins. In addition, these materials were selected as one of three pilot projects for the commercialization of NASA Glenn-developed technologies under the Glenn Alliance for Technology Exchange, a joint program between NASA Glenn, GliTech, and the Ohio Aerospace Institute.
Dr. Chuang has published more than 50 papers in refereed journals and conference proceedings and has been awarded seven U.S. patents for high-temperature polymer related technologies. Her accomplishments have been recognized through numerous highly prestigious NASA and national awards including an R&D-100 Award (2003), a NASA Space Act Award and the NASA Exceptional Achievement Medal (2000).
