Dr. Ajit K. Roy, a Computational Group Leader at the Materials and Manufacturing Directorate at Air Force Research Laboratory will give a seminar titled "Vitrimer Polymer Composites – Self-healing Aerospace Materials" to the interested faculty and students at Discovery Park.

Abstract

The repair of traditional thermoset composites used in aerospace systems is labor intensive, time consuming and costly due to its irreversible polymer cross-linking kinetics.  To alleviate this serious deficiency in thermoset polymers, a new class of covalent adaptable networks polymers, called vitrimers, have emerged to enable remote reconfigurable of chemical bonds to enable remote healing (repair) of thermoset composites.  Vitrimers can be thermally re-processed in a liquid state without losing network integrity resulting in its controllable malleability and re-processibility assembling thermosets (epoxy) by welding via external stimuli is highly desirable in aerospace applications, especially when direct heating is not an option for the repair (heat-sensitive components). However, slow covalent reaction dynamics, inherent brittle characteristics, a limited number of covalently adaptable networks, and a lack of photo-activity are some of the fundamental drawbacks to vitrimers, and hence is not readily attractive to many self-repair and composite recycling applications. In this talk, our approaches towards accelerating the chemical bond formation (regeneration) kinetics, thus in-turn to reduce the self-healing (repair) time will be presented.  The influence of incorporating nano constituents to vitrimers to enhance the self-healing kinetics will also be discussed.

Bio

Dr. Roy is a Computational Group Leader at the Materials and Manufacturing Directorate at AFRL.  His research area is on materials innovations and development in structural, thermal, and electronic materials.  His focus is in integrating multiscale computational methods to materials processing for accelerated materials development and technology transition.  He pioneered carbon foam technology and nano-porous carbon as multifunctional materials for coatings, flexible electronics, and battery electrodes.  His durable thermal interface concept transitioned to commercial product. He is a recipient of ASME John J. Montgomery Award for Distinguished Innovation in Aerospace, ASC Outstanding Research Award, Fellow of AFRL, AIAA, ASME, and ASC, and serves in journal editorial boards, and advisory panels. He received his Ph.D. in engineering mechanics from University of Minnesota in 1985.