Thermal, electrical and magnetic studies of magnetite filled polyurethane shape memory polymers

Razzaq, Muhammad Yasar; Anhalt, M.; Frormann, Lars; Weidenfeller, B.

doi:10.1016/j.msea.2006.08.083

Cited by 199 publications

(101 citation statements)

References 25 publications

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“…The reason for this phenomenon is that with the increasing content of Fe 3 O 4 nanoparticles, the composites can produce more heat to let the temperature reach or near the shape transition temperature where the magnetic field response time and recovery time decrease while the shape recovery rate increases. So the recovery rate of the samples increment with Fe3O4 nanoparticles content increasing [26]. It can be concluded that more nanoparticles in SBS/LLDPE blends can lead to a shorter magnetic field response time and less stress relaxation so that samples can attain a higher shape recovery rate.…”

Section: Magnetically Induced Shape Recovery Of Fe 3 O 4 /Sbs/lldpe Cmentioning

confidence: 89%

Shape Memory Polymer Composites of Poly(styrene-b-butadiene-b-styrene) Copolymer/Liner Low Density Polyethylene/Fe3O4 Nanoparticles for Remote Activation

Wang

Tian

2016

Applied Sciences

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Magnetically sensitive shape memory poly(styrene-b-butadiene-b-styrene) copolymer (SBS)/liner low density polyethylene (LLDPE) composites filled with various contents of Fe 3 O 4 nanoparticles were prepared. The influence of the Fe 3 O 4 nanoparticles content on the thermal properties, mechanical properties, fracture morphology, magnetic behavior, and shape memory effect of SBS/LLDPE/Fe 3 O 4 composites was systematically studied in this paper. The results indicated that homogeneously dispersed Fe 3 O 4 nanoparticles ensured the uniform heat generation and transfer in the alternating magnetic field, and endowed the SBS/LLDPE/Fe 3 O 4 composites with an excellent magnetically responsive shape memory effect. When the shape memory composites were in the alternating magnetic field (f = 60 kHz, H = 21.21 kA·m −1 ), the best shape recovery ratio reached 99%, the shape retention ratio reached 99.4%, and the shape recovery speed increased significantly with the increment of Fe 3 O 4 nanoparticles. It is anticipated that tagging products with this novel shape memory composite is helpful for the purpose of an intravascular delivery system in Micro-Electro-Mechanical System (MEMS) devices.

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Section: Magnetically Induced Shape Recovery Of Fe 3 O 4 /Sbs/lldpe Cmentioning

confidence: 89%

Shape Memory Polymer Composites of Poly(styrene-b-butadiene-b-styrene) Copolymer/Liner Low Density Polyethylene/Fe3O4 Nanoparticles for Remote Activation

Wang

Tian

2016

Applied Sciences

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“…Narendra Kumar et al -eXPRESS Polymer Letters Vol.6, No.1 (2012) [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] …”

Section: Recovery By Environmental Heatingmentioning

confidence: 99%

“…Three different mechanisms of heat generation have to be considered; eddy current losses (which are a minor effect as e.g. magnetite has very low electrical conductivity), hysteresis losses (during reversal of magnetization), and rotational losses (related to rotation of magnetic moments relative to the surrounding described by Neel and Brownian effects) [37,38]. In the current study, we explored, whether the shape-memory properties of triple-shape nanocomposites achieved by thermal and indirectly by magnetical stimulation of SME could be adjusted by variation of the applied programming protocols.…”

mentioning

confidence: 99%

Shape-memory properties of magnetically active triple-shape nanocomposites based on a grafted polymer network with two crystallizable switching segments

Kumar¹,

Kratz²,

Behl³

et al. 2012

Express Polym. Lett.

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Shape-memory polymers (SMP) and composites thereof belong to the class of actively moving polymers, which have the capability of storing one (dualshape) [1][2][3][4][5][6], two (triple-shape) [7][8][9][10][11][12][13] or multiple (multiple-shape) [14] stable temporary shapes and recover their original or other temporary shapes when exposed to an external stimulus. The field of SMP research has developed rapidly over the last years [6,[15][16][17][18][19][20][21][22][23][24][25] and it has become apparent that these functional polymers are motivating novel applications. Thermo-sensitive SMP contain physical or chemical network-points, which determine their original shape, while each temporary shape is fixed by switching domains associated to a thermal transition temperature T trans , that can be a glass transition (T g ) or a melting transition (T m ) [16,17]. The process for programming of a temporary shape is called 'shapememory creation procedure' (SMCP) and can be realized e.g. by deforming the material to an extension of ! m at T > T trans and cooling to T < T trans while keeping the deformation, which then is fixed temporarily by solidification of the related set of switching domains [26]. The recovery of the original shape is named shape-memory effect (SME), which is typically induced by increasing the environmental temperature (T env ) [3,5,27,28] Abstract. Thermo-sensitive shape-memory polymers (SMP), which are capable of memorizing two or more different shapes, have generated significant research and technological interest. A triple-shape effect (TSE) of SMP can be activated e.g. by increasing the environmental temperature (T env ), whereby two switching temperatures (T sw ) have to be exceeded to enable the subsequent shape changes from shape (A) to shape (B) and finally the original shape (C). In this work, we explored the thermally and magnetically initiated shape-memory properties of triple-shape nanocomposites with various compositions and particle contents using different shape-memory creation procedures (SMCP). The nanocomposites were prepared by the incorporation of magnetite nanoparticles into a multiphase polymer network matrix with grafted polymer network architecture containing crystallizable poly(ethylene glycol) (PEG) side chains and poly(!-caprolactone) (PCL) crosslinks named CLEGC. Excellent triple-shape properties were achieved for nanocomposites with high PEG weight fraction when two-step programming procedures were applied. In contrast, single-step programming resulted in dual-shape properties for all investigated materials as here the temporary shape (A) was predominantly fixed by PCL crystallites.

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“…Ferrite spinels, especially magnetite-like solid materials, are the most important ferrimagnetic materials for industrial applications [1], e.g., as high-density magnetic recording media [2], microwave devices [3], catalysts in selective catalytic reduction [4] and high temperature water-gas shift reaction [5], and ferrofluids in heat transfer [6]. Certainly for these applications, the thermal stability of magnetite is quite important.…”

Section: Introductionmentioning

confidence: 99%

The influence of substituting metals (Ti, V, Cr, Mn, Co and Ni) on the thermal stability of magnetite

Liang

Zhong

Tan

et al. 2012

J Therm Anal Calorim

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In this paper, a systematic study on the influence of substituting metals on the thermal stability of magnetite was carried out. Six series of substituted magnetite (Fe 3-x M x O 4 , M = Ti, V, Cr, Mn, Co and Ni) and Ti-V co-doped magnetite were prepared by a precipitationoxidation method, followed by the characterization of X-ray diffraction (XRD), X-ray absorption near-edge structure (XANES) spectroscopy and thermogravimetry and differential scanning calorimetry (TG-DSC) analyses. XRD patterns confirmed the formation of samples with spinel structure and XANES probed the valence and site occupancy of the substituting ions. From the TG-DSC analysis results, the substitution of Ti 4? , Mn 2? , Co 2? and Ni 2? stabilizes the magnetite structure, while V 3? and Cr 3? do not show such an effect. For the thermal stability of maghemite, V 3? has a negative effect while the other studied ions show a positive effect. In Ti-V co-doped magnetites, the influence of Ti 4? and V 3? on the thermal stability of magnetite is similar to the case of their singlemetal-substituted magnetites. The mechanism about the thermal stability change of magnetite by metal substitution was also discussed. The obtained results will be of high importance for the industrial applications of magnetite.

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Thermal, electrical and magnetic studies of magnetite filled polyurethane shape memory polymers

Cited by 199 publications

References 25 publications

Shape Memory Polymer Composites of Poly(styrene-b-butadiene-b-styrene) Copolymer/Liner Low Density Polyethylene/Fe3O4 Nanoparticles for Remote Activation

Shape Memory Polymer Composites of Poly(styrene-b-butadiene-b-styrene) Copolymer/Liner Low Density Polyethylene/Fe3O4 Nanoparticles for Remote Activation

Shape-memory properties of magnetically active triple-shape nanocomposites based on a grafted polymer network with two crystallizable switching segments

The influence of substituting metals (Ti, V, Cr, Mn, Co and Ni) on the thermal stability of magnetite

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