Polymer Nanocomposites for Shape-Memory Applications

Abstract

The dynamic response of the materials to the external stimuli makes it intelligent or smart, and the smart materials have promising applications in many areas. Shape-memory polymers (SMPs), a class of smart materials, exhibit a rapid change from a normal rigid state to a stretchy elastic state and then come back to the original state in the presence of external stimulus. SMPs have several advantages which include multiple sensitivity of the materials, highly flexibility in programming, various structural designs of materials, fine-tuning of the property by proper blending, and formation of composite. Still SMPs have many disadvantages, including poor mechanical properties, low shape fixity and poor shape recovery stress, and shape recovery ratio. Therefore, the development of shape-memory nanocomposites is a matter of concern to improve the shape-memory behavior, stiffness, etc. Various SMP nanocomposites have been developed by incorporation of carbon nanofiber (CNF), carbon nanotube (CNT), nanoclay, nanosilicon carbide, carbon black, and inorganic fillers into the polymer matrix. Incorporation of nanoparticles leads to the development of electrical-sensitive, light-sensitive, magnetic-sensitive, and water-/solvent-sensitive SMP nanocomposites with special features.