Title: Influence of the Degree of Crystallinity on Moisture Uptake and Mechanical Properties of AS4/PEKK

Authors: Sandi Miller, Paula Heimann, Meelad Ranaiefar, Daniel Gorican, Javier Buenrostro, Daniel Scheiman, Joseph Pinakidis, Michael Pereira

DOI: 10.33599/nasampe/c.24.0301

Abstract: Application of polymer matrix composites in extreme environments is limited by material performance in elevated temperature and wet conditions. Thermoplastic composites (TPCs) used for structural aerospace applications are typically semi-crystalline where the mechanical properties are influenced by the degree of crystallinity (DOC) and the DOC is dependent on the manufacturing process. While the low moisture absorption of TPCs has been documented in the literature a reduction in mechanical properties has also been reported following conditioning in a hot/wet environment. For this work, AS4/PEKK test coupons were manufactured with both fully crystallized (25%-30%) and partially crystallized (10%-15%) matrices. All coupons were tested in compression and in-plane shear at room temperature and under elevated temperature/wet (ETW) conditions. The influence of crystallinity and hot/wet exposure on matrix dominated mechanical properties of AS4/PEKK is reported.

References: 1. G. Gardiner, “Consolidating thermoplastic composite aerostructures in place, Part 2,” Composites World, 27 2 2018. [Online] Available: https://www.compositesworld.com/articles/consolidating-thermoplastic-composite-aerostructures-in-place-part-2. 2. M Russello, G. Catalanotti, S. Hawkins and B. Falzon, “Resistance welding of carbon fibre reinforced PEKK by means of CNT webs,” Journal of Composite Materials, 2022. 3. M. Wynn and N Zobeiry, “Investigating the effect of temperature history on crystal morphology of thermoplastic composites using in situ polarized light microscopy and probabilistic machine learning”, Polymers 2023, 15(1). 4. B. Grimsley et al, “In-situ consolidation automated fiber placement of thermoplastic composites for high-rate aircraft manufacturing”, SAMPE 2022 Charlotte, NC. 5. M. Donough, et. al, “Process modelling of in-situ consolidated thermoplastic composite by automated fibre placement- A review”, Composites Part A: Applied Science and Manufacturing, 163, 2022. 6. T. Slange, “Rapid manufacturing of a tailored spar by AFP and stamp forming”, ITHEC 2018. 7. N. Reynolds, S. Awang-Ngah, G. Williams, “Direct processing of structural thermoplastic composites using rapid isothermal stamp forming”, Appl Compos Mater, 27, 2020. 8. D. Howell and S. Fukumoto. ""Compression molding of long chopped fiber thermoplastic composites."" Proceedings of the CAMX Conference Proceedings, Orlando, FL, USA. 2014. 9. S. Alwekar, R. Ogle, S. Kim, and U. Vaidya, ""Manufacturing and characterization of continuous fiber-reinforced thermoplastic tape overmolded long fiber thermoplastic."" Composites Part B: Engineering 207 (2021). 10. I.F. Villegas and G. Palardy, “Ultrasonic Welding of Thermoplastic Composite Coupons for Mechanical Characterization of Welded Joints through Single Lap Shear Testing”, J Vis Exp. 2016 Feb 11;(108). 11. C. Butler, R. McCullough, R. Pitchumani and J. Gillespie Jr, “An analysis of mechanisms governing fusion bonding of thermoplastic composites”, J. Thermopl Compos Mat., 11, 1998. 12. N.L. Batista et. al., “Correlation between degree of crystallinity, morphology and mechanical properties of PPS/carbon fiber laminates”, Materials Research 2016; 19(1). 13. H. Perez-Martin, et. al., “Effect of crystallinity and morphology on the mechanical properties of CF/PEKK composites manufactured under compression moulding and automated tape placement”, MaterialsToday Commun. 36, 2023. 14. S.-L. Gao and J.-K. Kim, “Cooling rate influences in carbon fibre/PEEK composites. Part 1/ Crystallinity and interface adhesion”, Composites: Part A 31, 2000. 15. M.F. Talbott, G.S. Springer, and L.A. Berglund, “The effects of crystallinity on the mechanical properties of PEEK polymer and graphite fiber reinforced PEEK”, J. Compos Mater. 21, 1987. 16. Aptiv Victrex PEEK film technology report, available online: https://www.professionalplastics.com/professionalplastics/content/downloads/PeekFilm.pdf 17. N. Guermazi, A. Ben Tarjem, I. Ksouri, H. F. Ayedi, Compos. Part B: Eng. 2016, 85, 294. 18. K. Shetty, R. Bojja, S. Srihari, Adv., Compos. Lett. 2020, 29, 2633366X2092652. 19. E. F. Sukur, S. Elmas, M. Seyyednourani, V. Eskizeybek, M. Yildiz, H. S. Sas, Polym. Compos. 2022, 43, 8396. 20. N. Z. Borba, J. F. dos Santos, S. T. Amancio-Filho, Compos. Struct. 2021, 255, 112871. 21. Syensqo (formally Solvay) technical datasheet, available upon request. https://www.syensqo.com/en/product/apc-pekkas4d 22. R.L Mazur, G.M. Candido, M.C. Rezende and E.C. Botelho, “Accelerated aging effects on carbon fiber PEKK composites manufactured by hot compression molding”, J. Thermoplastic Compos. Mater. 2016, Vol 29(10) 1429-1442. 23. E.F Sukur, S. Elmas, V. Eskizeybek, H.S. Sas, M. Yildiz, “An experimental implication of long-term hot-wet-aged carbon fiber/polyether ketone ketone composites: The impact of automated fiber placement process parameters and process-induced defects. 24. N.L. Batista, M.C. Rezende, and E.C. Botelho, “The influence of crystallinity on the weather resistance of CF/PEEK composites”, Appl. Compos. Mater. (2021) 28:235-246. 25. G. Lesimple, I. Iliopoulos, J.B. Marijon, and B. Fayolle, “Full characterization of water transport properties in polyetherketoneketone (PEKK)”, ACS Appl. Polym. Mater. 2023, 5, 302−310.

Conference: CAMX 2024 | San Diego CA

Publication Date: 2024/9/9

SKU: TP24-0000000301

Pages: 11

Price: $22.00