Research progress in modification of shape memory polymer

Shape memory polymer (SMP) is a kind of intelligent material with excellent performance, which can change into temporary shape after sensing external stimuli, and can revert to the initial shape when external conditions change. It has been widely used in biomedicine, aerospace and other fields. However, SMP usually has a series of problems such as poor mechanical properties, insufficient recovery stress, inherent viscoelasticity and low intrinsic thermal conductivity of polymers, which limit its application range. In recent years, scholars have conducted a lot of research on the modification of SMP. This paper reviews the modification progress of shape memory polymers, including molecular structure modification, polymer blending, addition of functional fillers (magnetic particles, conductive metal particles, C-containing multifunctional materials, microwave sensitive particles), etc. Among them, molecular structure modification is the key strategy to provide suitable recovery stress for SMP. The blending method and the addition of functional fillers improve the inherent performance of SMP while providing more response ways. In addition, the application of modified SMP is introduced, and the potential development direction of SMP in the future is forecasted.