Effect of PEKK oligomers sizing on the dynamic mechanical behavior of poly(ether ketone ketone)/carbon fiber composites. Issue 24 (17th December 2019)

• Record Type: Journal Article
• Authors: Alexandre, Mike Abidine; Dantras, Eric; Lacabanne, Colette; Perez, Emile; Franceschi, Sophie; Coudeyre, Damien
• Is Part Of: Journal of applied polymer science. Volume 137:Issue 24(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-12-17
• Subjects: composites -- mechanical properties -- structure–property relationships -- thermoplastics; Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.48818
• Languages: English
• ISSNs: 0021-8995

Abstract

ABSTRACT: Poly(ether ketone ketone) (PEKK)/unidirectional carbon fiber (CF) composites have a poor interface. Accordingly, PEKK oligomer (PEKKo) sizing with a chemical compatibility with PEKK is proposed for promoting interfacial interactions in order to enhance mechanical performances. The thermal stability until 500 °C has been shown by thermogravimetric analysis (TGA). In order to compare static and dynamic sizing methods, "lab sizing" and "pilot sizing" were carried out. Scanning electron microscopy images of freeze fractures of PEKK/unsized CF, PEKK/PEKKo lab‐sized CF and PEKK/PEKKo pilot‐sized CF show that the PEKKo sizing causes an improvement of fiber/PEKK interactions, regardless of the sizing method. Indeed, in both cases, there is a continuity of matter at the interface while we observe a poor wetting of CF by matrix in PEKK/unsized CF. Dynamic mechanical relaxations in shear were analyzed as a function of temperature. The increase of storage modulus upon sizing is observed for both methods but it is more important for PEKKo pilot sizing. In the same way, the mechanical energy loss increases, it reflects the optimization of stress transfer between matrix and fibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48818. Abstract : Mechanical moduli as function of temperature and sizing treatment.