Development of Advanced Surface Treatments for Astroquartz Fibers

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Advanced Materials The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. OBJECTIVE: The objective of this project is to develop advanced coupling agents and surface treatments for Astroquartz fibers in order to increase the environmental and thermal durability of various Polymer Matrix Composite systems, which include a range of resin matrices from 350 degree Fahrenheit-curing epoxies to advanced polyimides. DESCRIPTION: Astroquartz-reinforced Polymer Matrix Composites (PMCs) are widely utilized on aircraft in radome applications due to excellent dielectric properties compared to other variants of glass and carbon fiber reinforcements. Although the mechanical performance requirements for these applications are not as demanding as other structural PMC components that utilize carbon fiber reinforcement, the environmental and thermal durability can limit their service life and significantly impact maintainability. Recent testing performed on various PMC systems with resin matrices ranging from 350 degree Fahrenheit-curing epoxies to advanced polyimides have exhibited extensive disbonds at the fiber-matrix interface after moisture and thermal conditioning. The objective of this project is to develop advanced coupling agents and surface treatments for Astroquartz fibers in order to increase the environmental and thermal durability of various Polymer Matrix Composite systems of interest. This SBIR should seek to identify key contributing factors for the limited durability in PMC systems of interest, develop optimized surface treatment processes for woven Astroquartz reinforcements, and develop tailored coupling agents that offer increased durability over the current state-of-the-art systems. PHASE I: As this is a Direct-to-Phase-II (D2P2) topic, no Phase I awards will be made as a result of this topic. To qualify for this D2P2 topic, the Government expects the applicant(s) to demonstrate feasibility by means of a prior Phase I-type effort that does not constitute work undertaken as part of a prior or ongoing SBIR/STTR funding agreement. The applicant(s) must show evidence of previous efforts demonstrating their capability to perform and develop advanced surface treatments for glass materials and/or aerospace fiber reinforcements, and to tailor coupling agents/fiber finishes to a wide range of polymer matrices. PHASE II: In the Phase II effort, the awardee(s) shall execute a comprehensive root cause analysis (RCA) to identify the key factors contributing to decreased mechanical performance in Astroquartz PMCs. Results from the RCA should inform either the development of optimized surface treatment processes to remove residual chemicals applied during the weaving process, or development of a tailored coupling agent to offer increased durability over the current state-of-the-art systems. The PMCs of interest shall include phenylethynyl-terminated polyimide and/or a 350 degree Fahrenheit-curing epoxy system. PHASE III DUAL USE APPLICATIONS: The awardee(s) can expect to pursue commercialization of the technology developed in Phase II by either partnering with an aerospace-grade weaver or prepreg supplier. Direct access with end users and government customers will be provided with opportunities to receive Phase III awards for providing the government additional research & development, or direct procurement of products and services developed in coordination with the program. In Phase-III, the awardee(s) must scale up the prototype technology, integrate it within the current supply chain, and perform a series of full-scale production runs. Lastly, the contractor must generate qualification data on the final Astroquartz fabric PMC. REFERENCES: Cloth, Quartz Finished for Resin Laminates, ASM3846-D, SAE international, 2022; KEYWORDS: Astroquartz; fiber sizing; fiber finish; fiber-resin interface; coupling agents; polymer matrix composites; epoxies; polyimides; thermosets;