Shape memory polymer nanocomposites

Gall, Ken; Dunn, Martin L.; Liu, Yiping; Finch, Dudley S.; Lake, Mark S.; Munshi, N. A.

doi:10.1016/s1359-6454(02)00368-3

Cited by 394 publications

(232 citation statements)

References 14 publications

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“…Compounds from shape-memory polymers and inorganic particles, including SiC particles (6, 7), carbon black (8,9), and nanotubes (10,11), were prepared. The incorporation of particles leads to enhanced mechanical properties (6,8) or electric conductivity (7,9).…”

mentioning

confidence: 99%

Initiation of shape-memory effect by inductive heating of magnetic nanoparticles in thermoplastic polymers

Mohr

Kratz

Weigel

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

756

586

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In shape-memory polymers, changes in shape are mostly induced by heating, and exceeding a specific switching temperature, T switch. If polymers cannot be warmed up by heat transfer using a hot liquid or gaseous medium, noncontact triggering will be required. In this article, the magnetically induced shape-memory effect of composites from magnetic nanoparticles and thermoplastic shapememory polymers is introduced. A polyetherurethane (TFX) and a biodegradable multiblock copolymer (PDC) with poly(p-dioxanone) as hard segment and poly( -caprolactone) as soft segment were investigated as matrix component. Nanoparticles consisting of an iron(III)oxide core in a silica matrix could be processed into both polymers. A homogeneous particle distribution in TFX could be shown. Compounds have suitable elastic and thermal properties for the shape-memory functionalization. Temporary shapes of TFX compounds were obtained by elongating at increased temperature and subsequent cooling under constant stress. Cold-drawing of PDC compounds at 25°C resulted in temporary fixation of the mechanical deformation by 50 -60%. The shape-memory effect of both composite systems could be induced by inductive heating in an alternating magnetic field (f ‫؍‬ 258 kHz; H ‫؍‬ 30 kA⅐m ؊1 ). The maximum temperatures achievable by inductive heating in a specific magnetic field depend on sample geometry and nanoparticle content. Shape recovery rates of composites resulting from magnetic triggering are comparable to those obtained by increasing the environmental temperature.nanocomposite ͉ shape-memory polymer ͉ stimuli-sensitive polymer S hape-memory polymers are able to recover their predefined original shape when exposed to an external stimulus. A prerequisite for the shape-memory effect is a preceding functionalization of the material to temporarily fix a mechanical deformation. Most shape-memory polymers are thermosensitive materials. The shape is actuated by exceeding a specific switching temperature, T switch (1). Thermoplastic shape-memory polymers have at least two separated phases, where the domains with the highest thermal transition (T perm ) stabilize the permanent shape by acting as physical netpoints. A second phase having another thermal transition T trans serves as switch. At temperatures above T trans the chain segments forming this phase are flexible and the material is highly elastic, whereas the flexibility of the chains below T trans is limited and enables the fixation of the temporary shape. T trans can either be a glass transition (T g ) or a melting temperature (T m ). Whereas T trans is the thermal transition of the switching segment phase, typically determined by differential scanning calorimetry (DSC), T switch is result of a thermomechanical test used to quantify the shape-memory effect.An important class of thermoplastic shape-memory polymers are polyurethanes. They often contain a hard segment from methylene bis(4-phenylisocyanate) (MDI) and 1,4-butanediol. Depending on the switching segment, T trans can be either a melting...

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mentioning

confidence: 99%

Initiation of shape-memory effect by inductive heating of magnetic nanoparticles in thermoplastic polymers

Mohr

Kratz

Weigel

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

756

586

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“…A well-dispersed nanoparticle in polymer matrix was confirmed by SEM as shown in Fig. 25a (Gall et al 2002). The stress-strain response of the epoxy/SiC nanocomposite at deformation temperature T d = 25°C is shown in Fig.…”

Section: Shape Memory Deployable Structuresmentioning

confidence: 81%

“…However, recovery stress is limited due to their lower stiffness. Recoverable stress improves by the addition of reinforcements (Gall et al 2002). Gall et al (2004) demonstrated the storage and release of internal stress in active PMNC with SiC nanoreinforcements.…”

Section: Shape Memory Deployable Structuresmentioning

confidence: 98%

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Polymer and ceramic nanocomposites for aerospace applications

2017

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This paper reviews the potential of polymer and ceramic matrix composites for aerospace/space vehicle applications. Special, unique and multifunctional properties arising due to the dispersion of nanoparticles in ceramic and metal matrix are briefly discussed followed by a classification of resulting aerospace applications. The paper presents polymer matrix composites comprising majority of aerospace applications in structures, coating, tribology, structural health monitoring, electromagnetic shielding and shape memory applications. The capabilities of the ceramic matrix nanocomposites to providing the electromagnetic shielding for aircrafts and better tribological properties to suit space environments are discussed. Structural health monitoring capability of ceramic matrix nanocomposite is also discussed. The properties of resulting nanocomposite material with its disadvantages like cost and processing difficulties are discussed. The paper concludes after the discussion of the possible future perspectives and challenges in implementation and further development of polymer and ceramic nanocomposite materials.

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“…Alternatively, one may improve the rubbery state elastic modulus by incorporating fillers within the SMP network. For instance, SMPs reinforced with SiC particles, carbon powders, carbon nanotubes (CNT), glass fibers or Kevlar fibers showed improved elastic modulus and shape recovery stress but decreased shape recovery percentage (Gall, 2000;Gall, 2002;Liu, 2009;Liu, 2004;Madbouly & Lendlein, 2010). Carbon-based nanoparticles, nanotubes, and nanofiber fillers also introduce electrical conductive properties to the SMPs, enabling potential electrical field-driven triggering.…”

Section: Smp With High Recovery Stressmentioning

confidence: 99%