As one of advanced functional materials, Shape Memory Polymer was studied on the shape recovery property, the shape fix property, and so on. However, it is difficult to comprehend the simple shape recovery behavior, because the viscoelastic and shape recover behaviors will occur simultaneously. Viscoelastic behavior is based on the entanglement effect on their polymeric chain, and the shape recovery behavior is based on the cross-link behavior. It is, therefore, necessary to divide these effects for understanding the viscoelastic and shape recovery behavior. The goal of this paper is to understand the viscoelastic and the simple shape recovery behavior, which depends on the cross-link, of the shape memory polymers.
