Effect of curing temperature on shape memory properties of graphene oxide‐carbon fiber hybrid‐reinforced shape memory polymer composites

Abstract In order to study the effect of curing temperature on the shape memory properties (SMPs) of GO‐CF hybrid‐reinforced SMPCs, eight sets of composites were prepared at different curing temperatures (60, 70, 80, 90, 100, 110, 120, and 130°C). The rheological and curing properties of the matrix, and the apparent density, porosity, microstructure, and SMPs of the composite were measured and analyzed, respectively. The results showed that at 100°C, the composite has the highest apparent density (1.52 g/cm³), the lowest porosity (0.47%), the best SMPs, the shape fixed rate of 99.13%, the shape recovery rate of 96.54%, and the maximum shape recovery force (5.15 N). The shape recovery speed and rate of shape recovery are also the fastest. This is because when the curing temperature is 100°C, the viscosity of the matrix can be kept at a low level, and the curing reaction rate is appropriate. This not only ensures that the matrix can be fully infiltrated into the fiber space but also obtains the matrix with appropriate crosslinking degree. Therefore, the microstructure of the prepared composite is ideal, which makes the matrix has a strong ability to restrain the expansion force of the fiber and a high efficiency of the transfer force and heat. Finally, in the test of SMPs, the composite showed higher SMPs. It was concluded that the SMPs of the composites were mainly affected by the infiltration effect of the matrix in the fiber. Highlights The microstructure of the composite was more ideal at 100 °C. The composite with the lowest porosity has the best shape memory properties. The high porosity weakens the heat and force transfer ability of the matrix. The shape memory properties of composites are the best prepared at 100 °C.