Shape memory based on composites and nanocomposites materials: from synthesis to application

Abstract Shape-memory polymers (SMPs) are a group of deformable and active materials that can exchange their shape between a temporary shape and their original shape. These polymers are programmed through shape-memory cycle that consists of two parts: programming part which offers shape-memory effect (SME), that is, temporary shape to the polymer, and the recovery part which returns it to its original shape. SMPs have low stiffness; therefore, SMPs produce large recoverable strains, but produce low recovery forces. For this cause, the consequence of SMP composites (SMPCs) has been investigated; SMPCs produce larger recovery forces as they are relatively rigid but have less recoverable strains. Moreover, strong shape-memory actuators can be produced if two different effects can be combined in a single structure. This chapter investigates the properties of SMPs in comparison with shape-memory alloys, and then the smart materials and their structure are discussed. After that, a brief background of SMPs and their categorizations is specified. The SMPCs and the different SMEs that are produced in SMPCs are also described. At the end, the advantages and disadvantages of SMPs and their composites in applications are summarized.