Freeze-thaw cycling effect on tensile properties of unidirectional flax fiber reinforced polymers. (1st October 2019) - Mak, Kenneth
Abstract: Natural fibre-reinforced polymers (FRP) research has grown over the years. With interest in retrofitting reinforced concrete, flax-FRP (FFRP) was investigated across 300 freeze-thaw cycles, while varying fibre type, resin type, manufacturing method and exposure conditions. Vacuum bag moulded FFRP exhibited the most severe degradation at a 8% strength reduction and 10% stiffness reduction. Damage initiation began after 100 cycles. Conversely, wet lay-up moulded specimens' higher resin content protected the flax from moisture. Equivalent glass-FRP showed no damage. FRP with epoxy and epoxidized pine oil blends (EPO) showed no initial mechanical difference. After exposure, epoxy showed signs of hydrolysis, whereas EPO showed further cross-linking.