Effect of cyclic tests on the shape memory performance of GO-CF hybrid-reinforced SMPC

This study investigated the effect of cyclic tests on the shape memory performance of graphene oxide-carbon fiber (GO-CF) hybrid-reinforced shape memory polymer composite (SMPC). The shape memory performance was evaluated by four indexes: shape fixation rate, shape recovery rate, recovery time, and maximum recovery force. The results showed that the service life of the GO-CF hybrid-reinforced SMPC prepared by the vacuum infiltration hot-press forming experimental system process (VIHPS) was 16 cycles. After 16 repetitions, the shape fixation rate decreased by approximately 6.6% and the shape recovery rate decreased by approximately 14.0%. At this time, the shape recovery rate was lower than 90%. The recovery time increased by 62.2% and the maximum recovery force decreased by 70.1%. The maximum recovery force exhibited the highest performance attenuation. Scanning electron microscopy (SEM) was used to photograph and analyze the microstructures of the samples under various cyclic tests. It was concluded that the main factor affecting the shape memory performance of GO-CF hybrid-reinforced SMPC is the life of fiber bundle. During cyclic testing, the fiber was prone to kinks, tensile damage and other defects, which increased the probability of reducing the length of the fiber bundle. Therefore, the probability of fiber fracture was improved, and the shape memory performance of the GO-CF hybrid-reinforced SMPC was attenuated.