Investigation on interlaminar properties of photopolymerizable resin repaired GFRPs during long-term acid ageing

Abstract

Fiber reinforced plastics (FRPs) are extensively utilized in various applications due to their excellent comprehensive properties. However, the weak interlaminar property and durability of FRPs have been repeatedly mentioned as limitations in applications that include complex loading conditions. The remediation of FRPs has recently become a research focus for lifetime extension and strength reversion. Photopolymerizable resins, as a novel matrix material and an alternative for thermal polymerizable resins, have the advantages of short operation time, low price, and low equipment requirements. This study investigated the durability in long-term acid atmosphere exposure environment of photo and thermal polymerizable resin repaired GFRP. External glass fabric patches impregnated with the photo or thermal polymerizable resins were attached to pre-damaged fundamental specimens to conduct the remediation, followed by room temperature (RT) or UV irradiation for curing processing. The repaired specimens were positioned in the laboratory-fabricated hermetically-sealed condensation device. The 10 vol.% sulphuric acid (pH[Formula: see text][Formula: see text][Formula: see text]0.76) was chosen as the source to generate the acidic atmosphere. The total ageing time was sustained for eight weeks (over 1300 h), and ILSS and DCB tests were performed every seven days, together with morphology observation. Better interlaminar properties retention and stability were revealed after eight weeks ageing for UV repaired specimens. The hardener is a factor that tends to increase the acid penetration rate, which is thought of as the mechanism of the better acid resistance of the UV repaired specimens.