Mechanisms of the Shape Memory Effect in Polymeric Materials

Abstract

Abstract:This review paper summarizes the recent research progress in the underlying mechanisms behind the shape memory effect (SME) and some newly discovered shape memory phenomena in polymeric materials. It is revealed that most polymeric materials, if not all, intrinsically have the thermo/chemo-responsive SME. It is demonstrated that a good understanding of the fundamentals behind various types of shape memory phenomena in polymeric materials is not only useful in design/synthesis of new polymeric shape memory materials (SMMs) with tailored performance, but also helpful in optimization of the existing ones, and thus remarkably widens the application field of polymeric SMMs.

Temperature memory effect and its stability revealed via differential scanning calorimetry in ethylene‐vinyl acetate within glass transition range

“…14,[16][17][18][19][20] Since any pre-straining (even elastic one), may cause a remarkable change in the phase transition temperatures of a SMA, [21][22][23] the TME in SMAs is mostly investigated via differential scanning calorimeter (DSC) test to reveal the previous heating stop temperature(s). [24][25][26][27][28][29] The TME has been recently proposed to monitor minor over-heating, even when the actual temperature fluctuation is in a random fashion, 30 with an accuracy of within 60.5 8C.…”

Smart Delivery Systems with Shape Memory and Self-Folding Polymers

“…The main difference of triple shape memory effect (TSME) is having one intermediate shape between its original and temporary shapes. If there is more than one intermediate shape, it is called multiple shape memory effect for a more complicated motion generation [40]. Polymers blends, grafting and blocking copolymers, SMP hybrids, and polymer laminates are some of the ways of managing the triple shape memory effects [41].…”

Shape memory polymer S-shaped mandrel for composite air duct manufacturing

“…The shape fixity and shape recovery ratio are two important factors to evaluate the shape memory effect of a SMP material [44]. A high shape fixity ratio can guarantee the surface accuracy of the mandrel, and a high shape recovery ratio can be beneficial for the extraction after curing.…”

“…A high shape fixity ratio can guarantee the surface accuracy of the mandrel, and a high shape recovery ratio can be beneficial for the extraction after curing. For a single cycle, the definition of shape fixity ratio (R f ) and shape recovery ratio (R r ) can be expressed as follows [44]:…”