Electroactive Shape‐Memory Polyurethane Composites Incorporating Carbon Nanotubes

Cho, Jae Whan; Kim, Jeong Won; Jung, Yong Chae; Goo, Nam Seo

doi:10.1002/marc.200400492

Cited by 572 publications

(328 citation statements)

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“…Another example for shape-memory polymers with T trans being a T m are block copolymers from poly(ethylene terephthalate) and poly(ethylene oxide) (5). 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%

“…If polymers cannot be warmed up by heat transfer using a hot liquid or gaseous medium, noncontact triggering will be required. Light-activation has been realized by heating thermally induced shape-memory polymers by irradiation (10,16,17). In addition, light-induced shape-memory polymers (18) have recently been developed, which use photosensitive functional groups as molecular switches.…”

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confidence: 99%

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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%

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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“…For example, a SMPU that can sustain shape recovery even at −30 o C has been reported. 13 An electroactive shape memory polymer composite containing carbon nanotube, 14,15 electromagnetic filler, 16,17 Ni chain, 18,19 have been already reported, demonstrating a quick shape recovery according to the application of electric current or electromagnetic field. In line with the above functional polymers, three well known fluorescent dyes, rhodamine, methylene violet, or fluorescein, were grafted to SMPU chain in this investigation to synthesize various fluorescent SMPUs as chemosensors.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Fluorescent Shape Memory Polyurethanes Grafted with Various Dyes

Chung¹,

Choi²,

Lee³

et al. 2011

Bulletin of the Korean Chemical Society

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Shape memory polyurethane (SMPU), grafted with a fluorescent dye (Rhodamine, Mehylene violet, or Fluorescein) through an allophanate linking, was tested for the fluorescence and the shape recovery effect. The main chain of SMPU was composed of 4,4'-methylenebis(phenylisocyanate) (MDI), poly(tetramethyleneglycol) (PTMG), and 1,4-butanediol (BD), and a fluorescent dye was connected through a second MDI linked to the carbamate moiety of the main chain. Three series of SMPU, differing according to their dye content, were prepared to compare their shape recovery and fluorescence properties. In tensile mechanical property, maximum stress increased up to 350% compared to the linear SMPU, and strain remained above 2000%. Shape recovery went to as high as 97%, and remained almost same after repetitive shape recovery test cycles. Finally, the fluorescence emission of SMPU was demonstrated in the luminescence spectrum and fluorescent light emission pictures. In addition, the response of SMPU to external stimuli such as metal ions was investigated.

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“…Fundamental research that concerned stimuli other than heat (e.g. light, electric current or alternating magnetic fields) and enabling the materials to possess more desirable properties-on-demand had been reported elsewhere (Lu et al, 2011a;Mohr et al, 2006;Li et al, 2012;Cho et al, 2005;Lu and Huang, 2013). Due to their practical and potential applications, SMP composites have been found to be highly desirable due to their tailorable properties after reinforcement.…”

Section: Introductionmentioning

confidence: 99%

Thermomechanical performance and shape recovery behaviour of shape memory polymer nanocomposite incorporated with hexagonal boron nitride

Yao

et al. 2017

PRT

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eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. Thermomechanical performance and shape recovery behaviour of shape memory polymer nanocomposite incorporated with hexagonal boron nitridePurpose -The purpose of the study reported in this paper was to develop an effective approach to significantly improve the thermomechanical properties of shape memory polymer (SMP) nanocomposites that show fast thermally responsive shape recovery.Design/methodology/approach -Hexagonal boron nitrides (h-BNs) were incorporated into polymer matrix in an attempt to improve the thermal conductivity and thermally responsive shape recovery behaviour of SMP, respectively. Thermally actuated shape recovery behaviour was recorded and monitored instrumentally. Originality/value -The outcome of this study may help fabrication of SMP nanocomposites with fast responsive recovery behaviour.

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Electroactive Shape‐Memory Polyurethane Composites Incorporating Carbon Nanotubes

Cited by 572 publications

References 23 publications

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

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

Investigation of Fluorescent Shape Memory Polyurethanes Grafted with Various Dyes

Thermomechanical performance and shape recovery behaviour of shape memory polymer nanocomposite incorporated with hexagonal boron nitride

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