Enhanced adhesion effect of epoxy resin on carbon fiber-reinforced Poly(etheretherketone) via surface initiated photopolymerization of glycidyl methacrylate

• Published in: Polymer (Guilford) Vol. 209; p. 123036
• Main Authors: Zhang, Yucheng, Hasegawa, Koichi, Kamo, Sota, Takagi, Kiyoka, Takahara, Atsushi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 17.11.2020; Elsevier BV
• Subjects: Adhesives; Brushes; Cantilever beams; Cantilevers; Carbon fiber reinforced plastics; Carbon fiber reinforcement; Carbon-epoxy composites; Carbon-fiber-reinforced PEEK; Composite structures; Epoxy adhesives; Epoxy resins; Fiber reinforced polymers; Irradiation; Luminous intensity; Mode I and Mode II fractures; Photopolymerization; Shear strength; Surface-initiated photopolymerization; Ultraviolet radiation; Epoxy adhesives; Surface-initiated photopolymerization; Carbon-fiber-reinforced PEEK; Mode I and Mode II fractures
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2020.123036

Adhesives for carbon fiber-reinforced poly (etheretherketone) (CFR-PEEK) have attracted the interest of researchers as an effective means for bonding this newly developed lightweight and high-performance composite structures. In this study, we developed a method to overcome the lack of interaction between adherends and adhesives through the modification of glycidyl methacrylate (GMA) brushes via surface-initiated photopolymerization. To achieve a better formation of PGMA brushes, some parameters of the surface-initiated photopolymerization, for example, light intensities (e.g., 2, 4, and 8 mW/cm2) and exposure durations (e.g., 15, 30, 45, 60, 90, 120 min) of ultraviolet (UV) treatment, were optimized. The joints using the adherends with an optimized PGMA layer exhibited more than a two-fold increase in the ultimate lap shear strength compared to that using the bare CFR-PEEK adherends, when a commercially available epoxy film adhesive, FM 309-1, is utilized. The influence of the UV intensities was further revealed via a double cantilever beam test, and the adherends with the modification under 4 mW/cm2 of UV irradiation for 2 h exhibited the best performance, owing to the higher grafting density of the PGMA brushes. [Display omitted] •Surface grafting of poly (glycidyl methacrylate) (PGMA) on CFR-PEEK was achieved.•Grafting of PGMA brushes reinforced the performance of the epoxy adhesive-bonded joints.•The lap shear strength of the joints using the adherents with modification is very high.•DCB test demonstrates the modified adherents exhibit very high mode I interlaminar toughness.