SBIR-STTR Award

Low Viscosity, High Strength Adhesive Materials with Low CTE
Award last edited on: 3/15/2023

Sponsored Program
SBIR
Awarding Agency
NASA : GSFC
Total Award Amount
$1,049,985
Award Phase
2
Solicitation Topic Code
S12.03
Principal Investigator
William Harrison

Company Information

NanoSonic Inc

158 Wheatland Drive
Pembroke, VA 24136
   (540) 626-6266
   info@nanosonic.com
   www.nanosonic.com
Location: Single
Congr. District: 09
County: Giles

Phase I

Contract Number: 80NSSC22PB108
Start Date: 7/19/2022    Completed: 1/25/2023
Phase I year
2022
Phase I Amount
$150,000
NanoSonic shall develop and demonstrate a novel low viscosity, UV curable adhesive that will possess high strength, high glass transition temperatures (Tg), and low coefficient of thermal expansion (CTE) for precise bonding. NanoSonic will validate the proposed cycloaliphatic epoxy silane adhesive material that is molecularly engineered for rapid, near room temperature photocuring and display low shrinkage during cure for precision alignment of Zerodur® and related low CTE ceramics for construction of telescopes. The proposed HybridSil low CTE epoxy silane adhesive will be molecularly tailored and formulated to possess the following properties: shear strength >4, 000 psi; tensile strength >6, 300 psi; glass transition >60 °C with near-room-temperature cure; viscosity ~12 Poise; and low outgassing. NanoSonic will develop low viscosity, crosslinked hybrid organic – inorganic UV cured epoxy adhesives that are molecularly engineered for exceptional adhesion to low CTE ceramics without high temperature processing, which may damage and cause stress increases leading to cracking. The silane crosslinking reactions can be used to introduction inorganic silicate nanoparticles in situ to modify the CTE, possibly eliminating the need for the typical high filler loading approach. The proposed HybridSil UV curable epoxy silane adhesive shall be engineered to rapidly set in minutes to afford submicron precision alignment of a telescope without prolonged support of placement equipment. The developed adhesive material shall be characterized for its chemical, thermal, and mechanical properties via real-time FTIR, rheometry, DSC, DMA, TMA, and Instron load frame. Potential NASA Applications (Limit 1500 characters, approximately 150 words): NASA needs low viscosity, UV curable adhesives with high strength, high glass transition temperatures and low coefficient of thermal expansion for precise bonding of Laser Interferometer Space Antenna (LISA) and other stable structure applications. These UV curable adhesives are used as potting and encapsulant materials in electronics. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): Aliphatic UV curable materials are used as wood finishings, adhesives, UV stable coatings, automotive protectant coatings, optical fibers coatings and cable jackets. Epoxy adhesive and resins with low CTE properties are used widely in optical and electrical components. Duration: 6

Phase II

Contract Number: 80NSSC23CA123
Start Date: 5/15/2023    Completed: 5/14/2025
Phase II year
2023
Phase II Amount
$899,985
NanoSonic has developed a low viscosity, UV curable epoxy technology for fast adhering of optical components to ceramic glass substrates. The aliphatic epoxy adhesive formulations have viscosities <10 Poise and the fully cured networks display glass transition temperatures higher than 70 °C using cationic photo initiation at ambient conditions. The adhesive formulation has successfully demonstrated curing inside of UV-opaque substrates via a dark cure mechanism. Dogbone specimens display tensile strength up to 36 MPa. Aluminum lapshear samples strength shows adhesive failure up to 26 MPa, while no ceramic glass lapshear failed in the bond area. CTE values for unfilled aliphatic epoxies were as low as 40 ppm °C. Anticipated

Benefits:
A low viscosity, UV curable adhesive system that possess high strength, high glass transition temperatures (Tg), and low coefficient of thermal expansion can be used in precise bonding of Laser Interferometer Space Antenna (LISA) and other stable structure applications, as well as encapsulants in electronics and UV-stable coatings. UV curable epoxy based-precursors and polymers are used as adhesives, UV-stable coatings, encapsulants for electronics, inks, and paints/varnishes applications. The low CTE and dielectric properties make these materials attractive for electronics and specialty application.