Title: Multi-Material Bonding Solid-State Bonding Via Bond Exchange Reactions

Authors: Jacob L. Meyer and Pixiang Lan

DOI: 10.33599/nasampe/c.19.0834

Abstract: Aromatic thermosetting copolyester (ATSP) intrinsically enables a unique solid-state adhesive bonding scheme based on a class of bond exchange reactions call interchain transesterification reactions (ITR) to robustly link metal articles and/or fiber reinforced composite parts with tailorable physical properties. The pre-polymer adhesive layer based on crosslinkable aromatic polyester oligomers is depositable over a very wide area via electrostatic powder coating. Solid-state was achieved bonding between fully cured ATSP-based parts within multimaterial (carbon fiber composite ply/metal) configurations. Following initial demonstration of proof-of-principle using a dynamic mechanical analyzer (DMA), ATSP coated (30-100 µm thickness) aluminum (Al) parts were joined under 1 to 23 MPa pressure at temperatures beyond glass transition of the corresponding ATSP matrix (>300°C). Next, this approach was adapted to produce adhesively bonded upscaled specimens. This was followed by physical characterization of the bonded samples to quantify the bonding strength, quantitative analysis of adhesive/cohesive failure modes as well as analyzing performance of bonded composite-metal multilayered structures over a broad temperature range. This was conducted in lap shear, 4-point bend, short beam shear (SBS), and Mode I fracture configurations. Mode I fracture toughness experiments were conducted at the metal/composite bondline. To investigate the thermomechanical reliability of the multimaterial composite structure, a thermomechanical cycle was applied on the specimen under 5 MPa static tensile load wherein the temperature was ranged between -150°C to 200°C. This solid-state bonding approach was then used to demonstrate fabrication of metal/composite multimaterial laminates using fully cured materials to produce complex shapes. X-ray micro computed tomography (micro-CT) was used to examine the internal structure, especially the bondline, and found no gaps or voids. Necessary activating conditions for the process will also be discussed.

References: 1. D Frich, J Economy, K Goranov, Aromatic copolyester thermosets: High temperature adhesive properties. Polymer Engineering & Science, 37(3), 541-548, 1997 2. D Frich, A Hall and J Economy, Nature of adhesive bonding via interchain transesterification reactions (ITR). Macromolecular Chemistry and Physics, 199(5), 913-921, 1998 3. B Vaezian, JL Meyer, C Mangun and J Economy, “Aromatic thermosetting copolyester composites for high temperature and cryogenic applications,” NASA SBIR Phase I NNX14CM10P – Final Report, 2014 4. KC Chuang, J Criss and EA Mintz, “Polyimide composites properties of RTM370 fabricated by vacuum assisted resins transfer molding (VARTM),” NASA Technical Report 20110008609, 2011. 5. S Ghose, KA Watson, RJ Cano, SM Britton, B.J. Jensen, J.W. Connell, H.M. Herring, and Q.J. Lineberry, “High temperature VARTM using LARC-PETI-9 polyimide resin,” High Performance Polymers 21, 653-672, 2009. 6. RJ Cano, BW Grimsley, BJ Jensen, and CB Kellen, “Processing and characterization of PETI composites fabricated by high temperature VARTM,” 36th International SAMPE Conference, 459-468, 2004. 7. KC Chuang, DM Revilock, JM Pereira, JM Criss and EA Mintz, “High temperature RTM 370 composites fabricated by RTM,” SAMPE Journal 49, 48-57, 2013. 8. C de Ruijter, E Mendes, H Boerstoel, S Picken, “Orientational order and mechanical properties of poly(amide-block-aramid) alternating block copolymer films and fibers,” Polymer 47, 8517-8526, 2006. 9. JL Meyer, M Bakir, P Lan, J Economy, I Jasiuk, G Bonhomme, AA Polycarpou, “Reversible Bonding of Aromatic Thermosetting Copolyesters for In‐Space Assembly,” Macromolecular Materials and Engineering, 1800647, 2019. 10. D Frich, K Goranov, L Schneggenburger, and J Economy. "Novel high-temperature aromatic copolyester thermosets: synthesis, characterization, and physical properties." Macromolecules 29, 7734-7739, 1996. 11. ASTM D3163-01(2014), Standard Test Method for Determining Strength of Adhesively Bonded Rigid Plastic Lap-Shear Joints in Shear by Tension Loading, ASTM International, West Conshohocken, PA, 2014, www.astm.org 12. ASTM D2344 / D2344M-16, Standard Test Method for Short-Beam Strength of Polymer Matrix Composite Materials and Their Laminates, ASTM International, West Conshohocken, PA, 2016, www.astm.org 13. ASTM D7264 / D7264M-15, Standard Test Method for Flexural Properties of Polymer Matrix Composite Materials, ASTM International, West Conshohocken, PA, 2015, www.astm.org 14. ASTM E831-14, Standard Test Method for Linear Thermal Expansion of Solid Materials by Thermomechanical Analysis, ASTM International, West Conshohocken, PA, 2014, www.astm.org 15. ASTM D5528-13, Standard Test Method for Mode I Interlaminar Fracture Toughness of Unidirectional Fiber-Reinforced Polymer Matrix Composites, ASTM International, West Conshohocken, PA, 2013, www.astm.org 16. ASTM D3762-03, Standard Test Method for Adhesive-Bonded Surface Durability of Aluminum (Wedge Test), ASTM International, West Conshohocken, PA, 2010, www.astm.org 17. EO Kutscha, PG Vahey, MA Belcher, PJ VanVoast, WB Grace, KY Blohowiak, FL Palmieri, JW Connell, Contamination and surface preparation effects on composite bonding, SAMPE 2017; 22-25 May 2017; Seattle 18. G Hartwig, Polymer properties at room and cryogenic temperatures. Springer Science & Business Media, 2013. 19. P Lan, R Gheisari, JL Meyer, and AA. Polycarpou. "Tribological performance of aromatic thermosetting polyester (ATSP) coatings under cryogenic conditions." Wear (2017). 20. Excerpted from http://www.amc.af.mil/News/Article-Display/Article/147235/advanced-composite-cargo-aircraft-makes-first-flight 21. Excerpted from http://www.compositesworld.com/articles/building-trust-in-bonded-primary-structures

Conference: CAMX 2019

Publication Date: 2019/09/23

SKU: TP19-0834

Pages: 15

Price: $30.00