Characristics of Shape Memory Composites Combined with Shape Memory Alloy and Shape Memory Polymer

In order to develop high functionality of shape memory materials, the shape memory composites combined with TiNi wire and shape memory epoxy were prepared, and the mechanical and thermomechanical properties were studied. The results showed the addition of TiNi wire increased the Young modulus and breaking strength both at room temperature and at elevated temperature. The composites maintained the rates of shape fixity and shape recovery close to 100%. The maximum recovery stress increased with increasing TiNi wire volume fraction, and obtained almost 3 times of the matrix by adding 1vol% TiNi wire.

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Investigate of Electrical Conductivity of Shape-Memory Polymer Filled with Carbon Black

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.47-50.714 ◽

2008 ◽

Vol 47-50 ◽

pp. 714-717 ◽

Cited By ~ 12

Author(s):

Xin Lan ◽

Jin Song Leng ◽

Yan Ju Liu ◽

Shan Yi Du

Keyword(s):

Electrical Conductivity ◽

Carbon Black ◽

Shape Memory ◽

Shape Recovery ◽

Volume Fraction ◽

Shape Memory Polymer ◽

Recovery Process ◽

Thermomechanical Properties ◽

Electrically Conductive ◽

New System

A new system of thermoset styrene-based shape-memory polymer (SMP) filled with carbon black (CB) is investigated. To realize the electroactive stimuli of SMP, the electrical conductivity of SMP filled with various amounts of CB is characterized. The percolation threshold of electrically conductive SMP filled with CB is about 3% (volume fraction of CB), which is much lower than many other electrically conductive polymers. When applying a voltage of 30V, the shape recovery process of SMP/CB(10 vol%) can be realized in about 100s. In addition, the thermomechanical properties are also characterized by differential scanning calorimetery (DSC).

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Actuation of Shape Memory Polymer by Resistive Heating of Carbon Nanopaper

Volume 14: Processing and Engineering Applications of Novel Materials ◽

10.1115/imece2009-11470 ◽

2009 ◽

Cited By ~ 1

Author(s):

Haibao Lu ◽

Yong Tang ◽

Jihua Gou ◽

Erin Chow ◽

Jinsong Leng ◽

...

Keyword(s):

Shape Memory ◽

Shape Recovery ◽

Carbon Nanofiber ◽

Volume Fraction ◽

Shape Memory Polymer ◽

Mechanical Analysis ◽

Thermomechanical Properties ◽

Paper Sheet ◽

Scanning Electron ◽

Properties Of Composites

To electrically activate the shape recovery in a styrene-based shape-memory polymer (SMP) by coating with conductive carbon nanofiber paper has been demonstrated in this paper. Carbon nanofibers in the form of paper sheet in combination with SMP significantly improve the electrical and thermal conductivity of polymer, leading to the actuation of SMP/nanopaper composite (with 15% volume fraction of carbon nanopaper, dimension of 10.0 cm × 0.5 cm × 0.3 cm) can be carried out by applying 8.4 V voltage, with response time of 140 s. Therefore, electrical conductivity of 6.6 S/cm is obtained. This approach, although demonstrated in styrene-based polymer, is applicable to other type of SMP materials. Furthermore, the morphologies of carbon nanofiber in the form of paper is observed by scanning electron microscopy, and the thermomechanical properties of composites are measured and analyzed by dynamic mechanical analysis.

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Shape fixity and shape recovery of polyurethane shape-memory polymer foams

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/146442070321700205 ◽

2003 ◽

Vol 217 (2) ◽

pp. 135-143 ◽

Cited By ~ 11

Author(s):

H Tobushi ◽

D Shimada ◽

S Hayashi ◽

M Endo

Keyword(s):

High Temperature ◽

Shape Memory ◽

Shape Recovery ◽

Shape Memory Polymer ◽

High Temperature Stress ◽

Thermomechanical Properties ◽

Recovery Stress ◽

Original Shape ◽

Number Of Cycles ◽

Shape Fixity

The thermomechanical properties of polyurethane shape memory polymer (SMP) foams were investigated experimentally. The results obtained can be summarized as follows. (1) By cooling the foam after compressive deformation at high temperature, stress decreases and the deformed shape is fixed. Stress decreases markedly in the region of temperature below the glass transition temperature Ts during the cooling process. (2) By heating the shape-fixed foam under no load, the original shape is recovered. Strain is recovered markedly at the temperature region in the vicinity of Tg. (3) The ratio of shape fixity is 100 per cent and that of shape recovery 98 per cent. Neither ratio depends on the number of cycles. (4) Recovery stress increases by heating under constraint of the fixed shape. Recovery stress is about 80 per cent of the applied maximum stress. Relaxed stress at high temperature is not recovered. (5) The shape deformed at high temperature is maintained for six months under no load at Tg’60 K without depending on maximum strain, and the original shape is recovered by heating thereafter. (6) If the deformed shape is kept at high temperature, the original shape is not recovered. The factors influencing the shape irrecovery are the holding conditions of strain, temperature, and time.

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Determination of Shape Fixity and Shape Recovery Rate of Carbon Nanotube-filled Shape Memory Polymer Nanocomposites

Procedia Engineering ◽

10.1016/j.proeng.2012.07.362 ◽

2012 ◽

Vol 41 ◽

pp. 1641-1646 ◽

Cited By ~ 17

Author(s):

Shahrul Azam Abdullah ◽

Aidah Jumahat ◽

Nik Rosli Abdullah ◽

Lars Frormann

Keyword(s):

Carbon Nanotube ◽

Shape Memory ◽

Polymer Nanocomposites ◽

Recovery Rate ◽

Shape Recovery ◽

Shape Memory Polymer ◽

Shape Fixity

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Temperature sensing and actuating capabilities of polymeric shape memory composite containing thermochromic particles

Pigment & Resin Technology ◽

10.1108/prt-06-2014-0046 ◽

2015 ◽

Vol 44 (4) ◽

pp. 224-231 ◽

Cited By ~ 7

Author(s):

Haibao Lu ◽

Yongtao Yao ◽

Long Lin

Keyword(s):

Shape Memory ◽

Information Dissemination ◽

Shape Memory Polymer ◽

Thermomechanical Properties ◽

Temperature Sensing ◽

Content Type ◽

Thermally Responsive ◽

Shape Memory Composites ◽

Potential Applications ◽

Shape Memory Composite

Purpose – This paper aims to create and to study multifunctional shape memory polymer (SMP) composites having temperature-sensing and actuating capabilities by embedding thermochromic particles within the polymer matrix. Design/methodology/approach – The multifunctional materials were fabricated following a process consisting of blending (of the thermochromic particles and the SMP at various ratios), mixing, degasing, moulding and thermal curing, prepared by incorporating thermochromic particles within the polymer. The effect of the thermochromic particles on the thermomechanical properties and thermally responsive shape memory effect of the resulting multifunction SMP composites were characterised and interpreted. Findings – It was found that exposure of the composites to temperatures above 70°C led to a pronounced change of their colour that was recorded by the thermal and electrical actuation approaches and was reproducibly reversible. It was also found that the colour of the composites was independent of the mechanical state of the SMP. Such effects enabled monitoring of the onset of the set/release temperature of the SMP matrix. Furthermore, the combination of thermochromic additive and the SMP resulted in significantly improved thermomechanical strength, absorption of infrared radiation and the temperature distribution of the SMP composites. Research limitations/implications – The temperature-sensing and actuating capabilities of the polymeric shape memory composites developed through this study will help to extend the field of potential applications of such composites to fields including sensors, actuators, security labels and information dissemination, where colour indication is an advantageous feature. Originality/value – The SMP composites capable of temperature sensing and actuating are novel.

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108 Shape Fixity, Shape Recovery and Secondary Shape Forming of Polyurethane-Shape Memory Polymer

The Proceedings of the Materials and processing conference ◽

10.1299/jsmemp.2006.14.27 ◽

2006 ◽

Vol 2006.14 (0) ◽

pp. 27-28

Author(s):

Hisaaki TOBUSHI ◽

Syunichi HAYASHI ◽

Yoshihiro EJIRI ◽

Toshimi SAKURAGI

Keyword(s):

Shape Memory ◽

Shape Recovery ◽

Shape Memory Polymer ◽

Shape Fixity

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Fabrication and Characterization of TiNi/AL Smart Composites

MRS Proceedings ◽

10.1557/proc-785-d7.1 ◽

2003 ◽

Vol 785 ◽

Author(s):

Gyu Chang Lee ◽

Jun Hee. Lee ◽

Young Chul Park

Keyword(s):

Composite Material ◽

Shape Memory ◽

Yield Stress ◽

Room Temperature ◽

Volume Fraction ◽

Matrix Material ◽

Al Alloy ◽

Alloy Matrix ◽

Strain Behavior ◽

The Matrix

ABSTRACTAn attempt was made to fabricate composite material of an Al alloy matrix reinforced by TiNi shape memory fiber using a hot-press method and to investigate its microstructures and mechanical properties. The analysis of SEM and EDS showed that the composite material had good interface bonding. The stress-strain behavior of the composite material was evaluated at room temperature and 363 K as a function of pre-strain, and it showed that the yield stress at 363 K is higher than that at room temperature. It is also found that the yield stress of the composite material increased with increasing the amount of pre-strain and depended on the volume fraction of the fiber and heat treatment. The smartness of the composite could be given due to the shape memory effect of the TiNi fiber, which generated compressive residual stress in the matrix material when heated after being pre-strained. Microstructural observation revealed that interfacial reactions occurred between the matrix and fiber, creating two intermetallic layers.

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Micro-buckling of carbon fibers in shape memory polymer composites under bending in the glass transition temperature region

Curved and Layered Structures ◽

10.1515/cls-2021-0009 ◽

2021 ◽

Vol 8 (1) ◽

pp. 96-108

Author(s):

Nilesh Tiwari ◽

AbdulHafiz A. Shaikh

Keyword(s):

Glass Transition ◽

Shape Memory ◽

Polymer Composites ◽

Volume Fraction ◽

Shape Memory Polymer ◽

Minimum Energy ◽

Three Dimensional ◽

Fiber Volume ◽

Half Wavelength ◽

The Matrix

Abstract The influence of a wide temperature range in the glass transition region of a shape memory polymer (SMP) matrix on micro-buckling of the fiber reinforcements in shape memory polymer composites (SMPC) under large bending deformation is described. Analytical expressions to estimate the strain energy, neutral strain surface, critical buckling surface and half wavelength of the buckled fibers in the SMPC are presented based on the minimum energy method. This study considers the reinforced fibers as three-dimensional elastic bodies and the matrix as a temperature stimulated flat plate. A comprehensive study was performed to understand the dynamic temperature behavior of the micro-buckled fibers and corresponding results were validated by previous works in the literature. The effects of fiber volume fraction and thickness of the SMPC plates on the half wavelength are also discussed along with the simultaneous influence of temperature on the parameters computed in the minimum energy analysis.

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

Pigment & Resin Technology ◽

10.1108/prt-01-2016-0016 ◽

2017 ◽

Vol 46 (1) ◽

pp. 79-83 ◽

Cited By ~ 5

Author(s):

Zhenghong Li ◽

Haibao Lu ◽

Yongtao Yao ◽

Long Lin

Keyword(s):

Thermal Conductivity ◽

Shape Memory ◽

Shape Recovery ◽

Hexagonal Boron Nitride ◽

Shape Memory Polymer ◽

Polymer Nanocomposite ◽

Thermomechanical Properties ◽

Content Type ◽

Thermally Responsive ◽

Thermally Actuated

Purpose The purpose of this paper is 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. Findings The results show that both glass transition temperature (Tg) and thermomechanical properties of the SMP nanocomposites have been progressively improved with increasing concentration of h-BNs. Analytical results also suggest that the fast-responsive recovery behaviour of the SMP nanocomposite incorporated with h-BNs was due to the increased thermal conductivity. Research limitations/implications A simple way for fabricating SMP nanocomposites with enhanced thermally responsive shape recovery based on the incorporation of h-BNs was developed. Originality/value The outcome of this study may help fabrication of SMP nanocomposites with fast responsive recovery behaviour.

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