Stimulation and reinforcement of shape-memory polymers and their composites: A review

2020 ◽  
pp. 089270572093077
Author(s):  
Ammar Boudjellal ◽  
Djalal Trache ◽  
Kamel Khimeche ◽  
Said Lotfi Hafsaoui ◽  
Ahmed Bougamra ◽  
...  

Shape-memory polymers (SMPs) and their composites (SMPCs), as a kind of smart materials, can respond to particular external stimulus and recover the original shape. They present outstanding features encompassing shape-memory effect, deformability, biocompatibility, variable stiffness, lightweight, and so on. They have attracted considerable research interest in recent years. Several stimulation methods to actuate the deformation of SMPs and SMPCs, of which the thermal stimulation is the common one, and many types of reinforcements have been developed over the past few years. It is revealed that the SMPC thermal and mechanical properties can be improved by introducing a number of reinforcements. Therefore, to well investigate the SMPC characteristics upon exposure to a specific external stimulus, a deep knowledge and understanding of the potential reinforcements as well as the available stimulation methods are crucial. In this review, reinforcements such as fibers, ceramics, and nanocarbons are first concisely presented. Next, numerous novel stimulation methods used to trigger the memory effect of the SMPCs are introduced, where the mechanisms of electrical, magnetic, thermal, light, and solution stimulations are briefly discussed. Finally, considering the increase of the number of interesting reinforcements as well as the efficient stimulation methods, SMPCs are expected to have great potential applications in different fields.

2016 ◽  
Vol 97 ◽  
pp. 93-99
Author(s):  
Jin Lian Hu ◽  
Harishkumar Narayana

Materials, structures and systems, responsive to an external stimulus are smart and adaptive to our human demands. Among smart materials, polymers with shape memory effect are at the forefront of research leading to comprehensive publications and wide applications. In this paper, we extend the concept of shape memory polymers to stress memory ones, which have been discovered recently. Like shape memory, stress memory represents a phenomenon where the stress in a polymer can be programmed, stored and retrieved reversibly with an external stimulus such as temperature and magnetic field. Stress memory may be mistaken as the recovery stress which was studied quite broadly. Our further investigation also reveals that stress memory is quite different from recovery stress containing multi-components including elastic and viscoelastic forces in addition to possible memory stress. Stress memory could be used into applications such as sensors, pressure garments, massage devices, electronic skins and artificial muscles. The current revelation of stress memory potentials is emanated from an authentic application of memory fibres, films, and foams in the smart compression devices for the management of chronic and therapeutic disorders.


Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2330
Author(s):  
Tao Xi Wang ◽  
Hong Mei Chen ◽  
Abhijit Vijay Salvekar ◽  
Junyi Lim ◽  
Yahui Chen ◽  
...  

The shape memory effect (SME) refers to the ability of a material to recover its original shape, but only in the presence of a right stimulus. Most polymers, either thermo-plastic or thermoset, can have the SME, although the actual shape memory performance varies according to the exact material and how the material is processed. Vitrimer, which is between thermoset and thermo-plastic, is featured by the reversible cross-linking. Vitrimer-like shape memory polymers (SMPs) combine the vitrimer-like behavior (associated with dissociative covalent adaptable networks) and SME, and can be utilized to achieve many novel functions that are difficult to be realized by conventional polymers. In the first part of this paper, a commercial polymer is used to demonstrate how to characterize the vitrimer-like behavior based on the heating-responsive SME. In the second part, a series of cases are presented to reveal the potential applications of vitrimer-like SMPs and their composites. It is concluded that the vitrimer-like feature not only enables many new ways in reshaping polymers, but also can bring forward new approaches in manufacturing, such as, rapid 3D printing in solid state on space/air/sea missions.


2020 ◽  
Vol 64 (4) ◽  
pp. 425-442
Author(s):  
Mathew J. Haskew ◽  
John G. Hardy

Shape-memory polymers (SMPs) enable the production of stimuli-responsive polymer-based materials with the ability to undergo a large recoverable deformation upon the application of an external stimulus. Academic and industrial research interest in the shape-memory effects (SMEs) of these SMP-based materials is growing for task-specific applications. This mini-review covers interesting aspects of SMP-based materials, their properties, how they may be investigated and highlights examples of the potential applications of these materials.


MRS Bulletin ◽  
2009 ◽  
Vol 34 (11) ◽  
pp. 848-855 ◽  
Author(s):  
Jinsong Leng ◽  
Haibao Lu ◽  
Yanju Liu ◽  
Wei Min Huang ◽  
Shanyi Du

AbstractShape-memory polymers (SMPs) offer a number of potential technical advantages that surpass other shape-memory materials such as shape-memory metallic alloys and shape-memory ceramics. The advantages include high recoverable strain (up to 400%), low density, ease of processing and the ability to tailor the recovery temperature, programmable and controllable recovery behavior, and more importantly, low cost. This article presents the state-of-the-art regarding SMPs. First, the architecture, type, and main properties of the traditional and recently developed SMPs are introduced. Second, structural and multifunctional SMP composites are summarized and discussed. These composites greatly enhance the performance of the SMPs and widen their potential applications. Finally, current applications of SMP materials in aerospace engineering, textiles, automobiles, and medicine are presented.


2008 ◽  
Vol 47-50 ◽  
pp. 690-693 ◽  
Author(s):  
Da Wei Zhang ◽  
Jin Song Leng ◽  
Yan Ju Liu

This paper is concerned about the synthesis of shape memory styrene copolymer and the investigation of the influence of radialization dosage on its shape memory effect. As one of novel actuators in smart materials, shape memory polymers (SMPs) have been investigated intensively. Styrene copolymer with proper cross-linking degree can exhibit shape memory effect (SME). In this paper, the influence of radialization on shape memory effect of styrene copolymer was investigated through altering the dosage of radialization. The radialization dosage of styrene copolymer was determined by changed radicalization time. The glass transition temperature (Tg) of styrene copolymerwas measured by Dynamic Mechanical Analysis (DMA). The shape memory performance of styrene copolymer with different radiated dosage was also evaluated. Results indicated that the shape memory polymer (SMP) was synthesized successfully. The Tg increased from 60°C to 65°C followed by increasing the radialization dosage. Moreover, the SMP experienced good SME and the largest reversible strain of the SMP reached as high as 150%. When heating above Tg+30°C (different copolymers performed different Tg), the shape recovery speed of the copolymers increased with increasing the radialization dosage. However, the recovery speed decreased with increasing the radialization dosage at the same temperature of 95°C.


RSC Advances ◽  
2015 ◽  
Vol 5 (76) ◽  
pp. 61601-61611 ◽  
Author(s):  
Xiang Shi ◽  
Xuemei Wang ◽  
Chao Fu ◽  
Xianghai Ran

Recently, as an important class of mechanically active smart materials, thermoplastic dual-shape memory polymers (SMPs) have attracted notable attention and can be fabricated in many different manufacturing techniques.


Author(s):  
L. Santo ◽  
L. Iorio ◽  
G. M. Tedde ◽  
F. Quadrini

Shape Memory Polymer Composites (SMPCs) are smart materials showing the structural properties of long-fiber polymer-matrix together with the functional behavior of shape memory polymers. In this study, SM carbon fiber reinforced (CFR) composites have been produced by using a SM interlayer between two CFR prepregs. Their SM properties have been evaluated in comparison with traditional structural CFR composites without the SM interlayer by using an especially designed test. Active and frozen forces are measured during a thermo-mechanical cycle in the three-point bending configuration. Experimental results show that SMPCs are able to fix a temporary deformed shape by freezing high stresses.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4246 ◽  
Author(s):  
Yujie Chen ◽  
Chi Chen ◽  
Hafeez Ur Rehman ◽  
Xu Zheng ◽  
Hua Li ◽  
...  

Shape-memory materials are smart materials that can remember an original shape and return to their unique state from a deformed secondary shape in the presence of an appropriate stimulus. This property allows these materials to be used as shape-memory artificial muscles, which form a subclass of artificial muscles. The shape-memory artificial muscles are fabricated from shape-memory polymers (SMPs) by twist insertion, shape fixation via Tm or Tg, or by liquid crystal elastomers (LCEs). The prepared SMP artificial muscles can be used in a wide range of applications, from biomimetic and soft robotics to actuators, because they can be operated without sophisticated linkage design and can achieve complex final shapes. Recently, significant achievements have been made in fabrication, modelling, and manipulation of SMP-based artificial muscles. This paper presents a review of the recent progress in shape-memory polymer-based artificial muscles. Here we focus on the mechanisms of SMPs, applications of SMPs as artificial muscles, and the challenges they face concerning actuation. While shape-memory behavior has been demonstrated in several stimulated environments, our focus is on thermal-, photo-, and electrical-actuated SMP artificial muscles.


2020 ◽  
Vol 31 (10) ◽  
pp. 1243-1283 ◽  
Author(s):  
Ebrahim Yarali ◽  
Ali Taheri ◽  
Mostafa Baghani

Shape memory polymers are a class of smart materials, which are capable of fixing their deformed shapes, and can return to their original shape in reaction to external stimulus such as heat. Also due to their exceptional properties, they are mostly used in four-dimensional printing applications. To model and investigate thermomechanical response of shape memory polymers mathematically, several constitutive equations have been developed over the past two decades. The purpose of this research is to provide an up-to-date review on structures, classifications, applications of shape memory polymers, and constitutive equations of thermally responsive shape memory polymers and their composites. First, a comprehensive review on the properties, structure, and classifications of shape memory polymers is conducted. Then, the proposed models in the literature are presented and discussed, which, particularly, are focused on the phase transition and thermo-viscoelastic approaches for conventional, two-way as well as multi-shape memory polymers. Then, a statistical analysis on constitutive relations of thermally activated shape memory polymers is carried out. Finally, we present a summary and give some concluding remarks, which could be helpful in selection of a suitable shape memory polymer constitutive model under a typical application.


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