Reversible and irreversible effects on the epoxy GFRP fiber-matrix interphase due to hydrothermal aging

• DOI: 10.1016/j.jcomc.2023.100395
• Publication Date: 2023-08-29T16:52:30Z
• Authors: Andrey E. Krauklis; Olesja Starkova; Dennis Gibhardt; Gerhard Kalinka; Hani Amir Aouissi; Juris Burlakovs; Alisa Sabalina; Bodo Fiedler
• Keywords: Interphase; Degradation; Plasticizer

Epoxy R-Glass Fiber-Reinforced Polymer (GFRP) composite plates were hydrothermally aged at 60 °C for 23, 75, and 133 days. The water content reached 0.97 wt%, 1.45 wt% 1.63 respectively. studied GFRP matrix was inert to hydrolysis or chain scission, allowing investigation of irreversible changes in the fiber-matrix interphase due hydrothermal aging upon re-drying. During each period, a subset specimens removed from bath dried chamber. weight loss drying explained with epoxy leaching (impurities), sizing-rich hydrolysis, glass fiber surface accumulated degradation products escaping, changing state bound free. influence on interfacial properties investigated. Lower strength (wet) samples attributed plasticization epoxy, (including formation hydrolytic flaws), surface. kinetics epoxy-compatible epoxysilane W2020 provided an estimate ca. 1.49%, 4.80%, 8.49% total degraded after days, At these conditions, interface lost 39%, 48%, 51% its strength. Upon re-drying specimens, significant part regained. Furthermore, upward trend observed, being 13%, 10% 3% strength, respectively; thus, indicating possibility partial recovery properties.