UNRAVEL PROCESSING-MECHANICS RELATIONS IN VITRIMER COMPOSITES WITH THERMALLY-DRIVEN BOND EXCHANGES VIA MOLECULAR ENGINEERING
Abstract
Virtimers are thermosetting polymers, but unlike traditional ones (e.g., epoxy-resin), their thermally induced crosslinks reconfigure by way of covalent bond exchanges with thermal stimuli. Exchangeable bonds offer great and unique benefits to thermoset-based aerospace composites, e.g., to self-repair and arrest cracks via molecular bridging. Despite benefits, our understanding of the dependence of vitrimer composite mechanics on molecular traits of vitrimer and practices to reduce manufacturing defects by means of exchangeable bonds is largely immature. To address this knowledge gap, our [Goal:] is to identify relations between molecular traits of vitrimers, e.g, mobility of the chains, their ability to form long range order and mechanics of their carbon fiber (CF) composites. We will work with the family of aromatic thermosetting copolyester (ATSP) vitrimers. This is driven by our ability to control its chemistry, required for systematic morphology-mechanics studies, and due to its high-temperature performance, withstanding ~400ºC, which later smoothen technology transfer. [Impact:] This work will lead to development of vitrimer composites with intrinsic reparability and high temperature performance, extending high-temperature applicability of polymer-based composites. [Anticipated outcome:] This work, for the first time, will generate knowledge on processing vitrimer composites with controllable defects and morphology-mechanics relations based on exchangeable bonds. [Approach:] The work will be done in three objectives according to composite hierarchies: matrix, matrix-CF interface, composite. Morphology of matrix and cure kinetics will be studied as a function of chain rigidity. The ability of ATSP vitrimers to form liquid crystal thermosets and regulate stress field along CF-matrix interface and its load bearing will be studied. Wet/dry composite processing, defect formation and mechanical properties, all in relation to the exchangeable bonds will be studied.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 20, 2023
- Source ID
- FA95502210496
Entities
People
- Mohammad Naraghi
Organizations
- Air Force Office of Scientific Research
- Texas Engineering Experiment Station
- United States Air Force