Development of Frontal Polymer Matrix Composites for Repair
Abstract
Project Abstract - Approved for Public Release.To provide the capability to repair composite structures in low-resourced and contested logistics environments, a quick-curing composite repair patch is proposed based on dicyclopentadiene (DCPD) resin cured by frontal reaction. DCPD polymer matrix composite offers suitable properties and high Tg, but conventionally has had challenges of ignition, front stalling or non-uniform cure state, and storage shelf life. Our team proposes a novel #catalyst ignition# approach which hasadvantages of not requiring a separate energy source for ignition (no added heat, UV or IR source needed), wide-area chemical-basedignition with short through-thickness front travel path, and potentially long shelf life since the catalyst is not premixed with the resin. Cure time is anticipated in the seconds to minutes timeframe (upon ignition). The objectives therefore are to perform basicresearch on the development of a robust and controllable process for creating composites for repair patches using our proposed novel #catalyst ignition# approach. A self-imposed constraint during process development is to not require any complex supporting powered equipment to enable repairs within a low-resourced environment. Proposed research activity will be conducted in stages: Stage 1 Resin-Only Study - demonstrate feasibility of the #catalyst ignition# approach using resin-only samples, establish process control andoptimization. Stage 2 Composite Study - apply Stage 1 results to processing development of high fiber loading composites (55-60% vol. fraction) with woven carbon and glass fibers, assess resulting properties and uniformity of cure as well as establish methods to spatially tune/control front propagation to achieve desirable end state. Stage 3 Adhesion Study - apply Stage 2 results to develop processes for forming strong adhesion attachment to composite substrates representative of Navy structures (autoclave cured carbon/epoxy). Stage 4 Implementation and Demonstration - as an example of use and to assess efficacy, composite panels will be repaired using our material approach using stacked step-lap circular patches (following standard repair design). Stage 5 Shelf Stability Study - materials will be stored at room temperature, hot, and other conditions for up to two years prior to testing for ignition and frontal curing performance as well as resulting physical and mechanical properties. The expected outcome of this proposed basic research study is to first verify the viability of the proposed #catalyst ignition# process, and then to determine an appropriate process for repair patches. This includes developing a key understanding of the chemistry, cure kinetics, and processing steps to achieve adequate and stable properties and adhesion. This would position the technology for future transition into application as a deployable product for quick repair (following further applied-level research and development). For the Navy (and DoD), success of this research will provide a repair material which can be applied and cured without complex heating equipment to obtain suitable properties and Tg.Furthermore, the approach involves materials that are stable at room temperature and it is anticipated that they can be stored for long durations. Ultimately, having repair processes that are simple to deploy based on materials that can be persistently available in forward-operating environments, increases the ability to quickly repair damage. Overall, this can increase the mission-readiness of system platforms having composite structures subject to damage. These repairs are not envisioned (at present) to be a final permanent repair, but an interim fix to allow for short-term continued use of the composite structure until major depot-level repairs canbe performed.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 24, 2025
- Source ID
- N000142512091
Entities
People
- Hyonny Kim
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego