Shape memory polymers for composites
Introduction
The shape memory effect (SME) is a special mechanical phenomenon usually described by the shape memory cycle (SMC). Fig. 1.1 shows a highly common shape memory cycle. SMC represents the mechanical process that embodies the shape memory effect of that kind of material, and a more exact definition will be explained later. The shape memory effect is common in polymers, but most examples are inferior. One class of polymers can provide excellent shape memory effects and they are predominantly used in shape memory applications. They are called shape memory polymers (SMPs). Shape memory polymers are active deformable materials that undergo large deformations, first mentioned by Vernon et al. in a dental patent in 1941 [1]. In the sixties, heat-shrinkable tubes entered the market [2,3]. Their applications have drawn substantial research attraction. As the seventies began, a number of commercial companies developed their own shape memory polymers [4]. Since the end of the last century, researchers have begun to systematically study shape memory polymers. The principle of shape memory has been increasingly elucidated, and diverse shape memory effects have been observed [5].
Taking the initiative to change shape is vitally necessary for animals and even other organisms. Compared to inorganic ceramics and metal materials, polymer materials show natural advantages such as lower density, better biological and organic compatibility, and easier modification and processing. Accordingly, shape memory polymers are blossoming in radiant splendor in the field of active polymers. Actively moving materials can be effectively deformed in shape by external stimulation [[6], [7], [8], [9]]. Examples such as shape memory polymers, electroactive polymers [10,11], photo-induced polymers [12], and hydrogels [13,14] have been the subject of substantial research. Actively moving materials are often categorized by response behavior, and the differences in properties between different actively moving materials are significant.
Shape memory polymers are materials driven by external stimuli that actively switch between multiple shapes. Compared with other materials, shape memory polymers have the advantages of high stress tolerance [15], the ability to undergo large deformations [2], a rich selection of driving methods (including heat 3456, light [7,8], electricity [[9], [10], [11]], magnetism [12,13] wetting [14], and pH [16]), excellent radiation resistance and good biocompatibility [17], which make them a research hotspot in the field of actively moving materials.
At present, shape memory polymers have many applications in aerospace [18], medicine [[19], [20], [21]], self-finishing smart textiles [22,23] and electronic devices [24], and self-assembling structure [[25], [26], [27]]. Specific applications, including low-impact release mechanisms in the aerospace field, large spatial deployable structures, shape memory polymer sutures, minimally invasive surgical instruments with good biocompatibility, the active deformation or self-finishing of textiles, electronic devices, and variable mandrels, which effectively solve the thorny problems of the corresponding fields, show the great power of shape memory polymers. The above applications involving composites will be described in detail in Section 5.
Section snippets
Basis of shape memory effect in polymers
In this section, the basic characteristics of shape memory polymers are reviewed, and the topic of shape memory polymer composites is not addressed. The majority of this section is thus a classic topic, which can be found in a standard shape memory polymer review. Therefore, this section is brief. More detailed description can refer to the supplementary documents.
This section does not discuss an important property of the shape memory polymer, the stimulation method. Because taking into account
Why use SMPCs instead of SMPs?
In general, the significance of composite materials is that several components complement each other, result in synergies, or improve or enrich the function of the matrix material. For shape memory polymers, composites are made with two basic objectives, i.e., reinforcement and finding new and effective stimulation methods. (For shape memory polymer composites, the stimulation can be more precise and highly selective, so more sophisticated shape memory behaviors can be achieved, such as the
The mechanics of SMPs and SMPCs
As mentioned earlier, the shape memory effect is a polymer mechanical behavior. With the principle of shape memory effect explained, increasing numbers of people are aware of the universality of this effect. Once it is recognized that the shape memory effect is to a considerable extent a process property, the description of the mechanical behavior becomes very urgent. There are significant differences in the shape memory behavior of polymers with respect to different programming and recovery
Applications of SMPCs
Applications have always been the focus of studies on shape memory polymers and their composites. During the 1960s, shape memory polymers gained their first large-scale applications, namely, the use of PE thermal contraction tubes [263,264], which now are made from nylon [265] or polystyrene [266] materials. Thermal contraction tubes have good flame retardance, insulation and temperature tolerance properties and have been widely used in insulated joint protection, harnesses and erosion
Conclusion and outlook
It is not appropriate to discuss shape memory polymers without discussing shape memory effect, so I hope that increasing numbers of people will be able to learn about the shape memory effect as a general phenomenon of polymer mechanics that occurs through the material learning of shape memory polymers, i.e., it is determined by the properties of the material and the external factors together. This concept can guide their design, especially in cases of active deformation behavior. We distinguish
Acknowledgement
This work is supported by the National Natural Science Foundation of China: Grant Nos. 11672086, 11772109 and 11632005.
Thanks to Xisu Wang for translating and collating some of the manuscripts in English. Thanks to Hongrui Suit finishing the article and the reference document format.
References (336)
- et al.
Facile tailoring of thermal transition temperatures of epoxy shape memory polymers
Polymer
(2009) - et al.
Synthesis and characterization of high temperature cyanate-based shape memory polymers with functional polybutadiene/acrylonitrile
Polymer
(2014) - et al.
Review of electro-active shape-memory polymer composite
Compos. Sci. Technol.
(2009) - et al.
Shape memory epoxies based on networks with chemical and physical crosslinks
Eur. Polym. J.
(2011) - et al.
Shape-memory polymers and their composites: stimulus methods and applications
Prog. Mater. Sci.
(2011) - et al.
A thermodynamical constitutive model for shape memory materials. Part I. The monolithic shape memory alloy
Int. J. Plast.
(1996) - et al.
The two way shape memory effect of shape memory alloys: an experimental study and a phenomenological model
Int. J. Plast.
(2000) - et al.
Thermomechanical constitutive model of shape memory polymer
Mech. Mater.
(2001) - et al.
Relaxation based modeling of tunable shape recovery kinetics observed under isothermal conditions for amorphous shape-memory polymers
Polymer
(2010) - et al.
Uniaxial deformation of overstretched polyethylene: in-situ synchrotron small angle X-ray scattering study
Polymer
(2007)
Effects of carbon black nanoparticles on twoway reversible shape memory in crosslinked polyethylene
Polymer
Properties and mechanism of two-way shape memory polyurethane composites
Compos. Sci. Technol.
Two way’shape memory composites based on electroactive polymer and thermoplastic membrane
Compos. Appl. Sci. Manuf.
Shape memory polymer based self-healing syntactic foam: 3-D confined thermomechanical characterization
Compos. Sci. Technol.
The two-way shape memory effect
Eng. Aspects Shape Mem. Alloy
The two-way shape memory effect and other “training” phenomena in Cu-Zn single crystals
Scripta Metall.
Magnetic field-induced reversible variant rearrangement in Fe–Pd single crystals
Acta Mater.
Novel vapor-grown carbon nanofiber/epoxy shape memory nanocomposites prepared via latex technology
Mater. Lett.
Mechanical and shape memory behavior of composites with shape memory polymer
Compos. Appl. Sci. Manuf.
Preparation and characterization of water-borne epoxy shape memory composites containing silica
Compos. Appl. Sci. Manuf.
Behavior of composites with shape memory polymer
Compos. Appl. Sci. Manuf.
Bending behavior of shape memory polymer based laminates
Compos. Struct.
Shape memory effect and mechanical properties of carbon nanotube/shape memory polymer nanocomposites
Compos. Struct.
Stiffness and vibration characteristics of SMA/ER3 composites with shape memory alloy short fibers
Compos. Struct.
Novel vapor-grown carbon nanofiber/epoxy shape memory nanocomposites prepared via latex technology
Mater. Lett.
Theoretical analysis and experiments of a space deployable truss structure
Compos. Struct.
Effect of different dimensional carbon nanoparticles on the shape memory behavior of thermotropic liquid crystalline polymer
Compos. Sci. Technol.
Process of Manufacturing Articles of Thermoplastic Synthetic Resins
High-strain shape-memory polymers
Adv. Funct. Mater.
Effect of a linear monomer on the thermomechanical properties of epoxy shape-memory polymer
Smart Mater. Struct.
Shape-memory polymers with adjustable high glass transition temperatures
Macromolecules
Light-induced shape-memory polymers
Nature
Light-controlled complex deformation and motion of shape-memory polymers using a temperature gradient
ACS Macro Lett.
Significantly reducing electrical resistivity by forming conductive Ni chains in a polyurethane shape-memory polymer/carbon-black composite
Appl. Phys. Lett.
Electrical conductivity of thermoresponsive shape-memory polymer with embedded micron sized Ni powder chains
Appl. Phys. Lett.
Initiation of shape-memory effect by inductive heating of magnetic nanoparticles in thermoplastic polymers
Proc. Natl. Acad. Sci. U.S.A.
Remote, fast actuation of programmable multiple shape memory composites by magnetic fields
J. Mater. Chem. C
Qualitative separation of the effect of the solubility parameter on the recovery behavior of shape-memory polymer
Smart Mater. Struct.
pH-induced shape-memory polymers
Macromol. Rapid Commun.
Biodegradable, elastic shape-memory polymers for potential biomedical applications
Science
Shape memory polymers and their composites in aerospace applications: a review
Smart Mater. Struct.
Shape-memory polymers as a technology platform for biomedical applications
Expet Rev. Med. Dev.
Development of a polymer stent with shape memory effect as a drug delivery system
J. Mater. Sci. Mater. Med.
Shape-memory polymers as a technology platform for biomedical applications
Expet Rev. Med. Dev.
A review of stimuli-responsive polymers for smart textile applications
Smart Mater. Struct.
Investigating smart textiles based on shape memory materials
Textil. Res. J.
Shape memory polymer-based self-healing triboelectric nanogenerator
Energy Environ. Sci.
Active materials by four-dimension printing
Appl. Phys. Lett.
A method for building self-folding machines
Science
3D printing of shape memory polymers for flexible electronic devices
Adv. Mater.
Cited by (224)
Thin-walled deployable composite structures: A review
2024, Progress in Aerospace SciencesHarnessing the power of carbon fiber reinforced liquid crystal elastomer composites for high-performance aerospace materials: A comprehensive investigation on reversible transformation and shape memory deformation
2024, Composites Part A: Applied Science and ManufacturingBiocompatible tissue-engineered scaffold polymers for 3D printing and its application for 4D printing
2023, Chemical Engineering JournalMagnetic- and light-responsive shape memory polymer nanocomposites from bio-based benzoxazine resin and iron oxide nanoparticles
2023, Advanced Industrial and Engineering Polymer ResearchStructural and damage analysis of a programmable shape memory locking laminate with large deformation
2023, Composites Part B: Engineering
- 1
These authors contributed equally to this work.