scholarly journals Effect of Nanofiller Dispersion on Morphology, Mechanical and Conducting Properties of Electroactive Shape Memory Poly(Urethane-Urea)/Functional Nanodiamond Composite

2015 ◽  
Vol 15 (4) ◽  
pp. 14-28 ◽  
Author(s):  
A. Kausar
Keyword(s):  
Electrical Conductivity ◽  
Tensile Strength ◽  
Shape Memory ◽  
Shape Recovery ◽  
Hard Segment ◽  
Soft Segment ◽  
Chain Extender ◽  
Solution Casting ◽  
Melt Blending ◽  
Solution Route

Abstract In this attempt, segmented poly(urethane urea) was prepared from polycaprolactone triol (soft segment), 1,3- bis(isocyanatomethyl)cyclohexane (hard segment) and 4,5-diaminophthalonitrile (chain extender). Acidfunctionalized nano-diamond was used as nano-filler. The nanocomposites were processed using solution casting and melt blending. Unique morphology was observed by SEM due to generation of crosslinked polyurethane and ND network. The s-PUU/ND 10 depicted 6 % increase in tensile strength compared with m-PUU/ND 10. 10 wt. % ND loading via solution route increased conductivity to 0.089 Scm-1 relative to m-PUU/ND 10 (0.057 Scm-1). Electrical conductivity of nanocomposites was enough to show electroactive shape recovery of 95 % (40 V).

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

2008 ◽  
Vol 47-50 ◽  
pp. 714-717 ◽  
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).

Modification of Polyurethane by Tung Oil Anhydride-Ester Polyol

2012 ◽  
Vol 554-556 ◽  
pp. 191-194 ◽  
Author(s):  
Han Zhou Sun ◽  
Xun Jun Du ◽  
Jin Hua Zhou ◽  
Lian Wu Xie ◽  
Yu Xiong Wu ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Tensile Strength ◽  
Heat Resistance ◽  
Hard Segment ◽  
Soft Segment ◽  
Morphological Structure ◽  
Elongation At Break ◽  
Tung Oil ◽  
Synthetic Resins ◽  
The World

Polyurethane (PU), one of the six main categories of synthetic resins, has been used extensively in industry all over the world. Tung oil anhydride-ester polyol (TOAEP), prepared from the China special vegetable oil, Tung oil, was introduced into PU structure. The mechanical property, heat-resistance and morphological structure of the modified PU were studied. Experimental results showed that the hardness and tensile strength of the modified PU increases as the dose of TOAEP increasing while the elongation at break decreases, and the heat-resistance has been improved after modification. The modified PU’s hard segment phase is compatible with the soft segment phase.

Synthesis and Characterization of a Bio-Compatible Shape Memory Polymer Blend for Biomedical and Clinical Applications

2014 ◽  
Author(s):  
Janice J. Song ◽  
Jennifer Kowalski ◽  
Hani E. Naguib
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shape Memory ◽  
Recovery Rate ◽  
Shape Recovery ◽  
Clinical Applications ◽  
Poly Lactic Acid ◽  
Shape Memory Properties ◽  
Shape Fixity ◽  
Recovery Temperature

Shape memory polymers (SMP) are a class of stimuli-responsive materials that are able to respond to external stimulus such as heat by altering their shape. Bio-compatible SMPs have a number of advantages over existing SMP materials and are being studied extensively for biomedical and clinical applications. Polymer blending has proved to be an effective method to improve the mechanical properties of polymers (such as tensile strength and toughness) as well as shape memory properties. In this study, we investigate the effect of blending two bio compatible polymers, thermoplastic polyurethane (TPU), a polymer with a high toughness and percent elongation, and poly-lactic acid (PLA), a stiff and strong polymer. The thermal, mechanical and thermo-mechanical (shape memory) properties of TPU/PLA blends were characterized in the following weight percent compositions: 80/20, 65/35, and 50/50 TPU/PLA. The TPU/PLA SMP blending was achieved with melt-blending and the tensile samples were fabricated with compression molding. The mechanical properties of each blend were studied at three different temperatures. The following thermo-mechanical (or shape memory) properties were also studied at each temperature: the shape fixity rate (Rf), shape recovery rate (Rr) and the effect of recovery temperature on the shape memory behavior. The microstructure of the polymer blends were investigated with an environmental scanning electron microscope (SEM). The results showed that the glass transition temperatures of the blends were similar to pure PLA. The toughness of the SMP blend increased with increasing TPU concentration and the tensile strength of the blend increased with PLA composition. The shape fixity rate of the TPU/PLA blend increased with increasing TPU content and the shape recovery rate increased with increasing deformation and recovery temperature. The various TPU/PLA SMP blends characterized in this study have the potential to be developed further for specific biomedical and clinical applications.

scholarly journals Shape memory polyurethanes based on recycled polyvinyl butyral. I. Synthesis and morphology

2013 ◽  
Vol 11 (12) ◽  
pp. 2058-2065 ◽  
Author(s):  
Tsvetomir Tsonev ◽  
Michael Herzog ◽  
Sanchi Nenkova
Keyword(s):  
Shape Memory ◽  
Hard Segment ◽  
Soft Segment ◽  
Polyvinyl Butyral ◽  
Mechanical Analysis ◽  
Attenuated Total Reflection ◽  
Polypropylene Glycol ◽  
Scanning Calorimetry ◽  
Chemical Crosslinks ◽  
Physical And Chemical

AbstractShape memory polyurethanes (SMPUs) were synthesized by 4,4′-diphenylmethane diisocyanate (MDI), hexane-1,6-diol (HD), polypropylene glycol (PPG), and recycled polyvinyl butyral (PVB). Dynamic mechanical analysis, differential scanning calorimetry and Fourier transformation infrared attenuated total reflection spectroscopy was used to characterize the poly (vinylbutyral-urethanes). Micro-phase domain separation of hard and soft segments and phase inversion were investigated. Increasing the hard segment content, i.e., average hard segment molecular weight, leads to an increase in the degree of micro-phase separation, hard domain order and crystallinity. The crystalline hard segment structures combined with the elastic nature of soft segment matrix provide enough physical and chemical crosslinks to have shape memory effect.

scholarly journals Hardness Modulated Thermoplastic Poly(ether ester) Elastomers for the Automobile Weather-Strip Application

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 525
Author(s):  
Su Hyeon Jeon ◽  
Jae Eon Jeong ◽  
Seongkyun Kim ◽  
Sungwan Jeon ◽  
Jin Woo Choung ◽  
...  
Keyword(s):  
Hard Segment ◽  
Soft Segment ◽  
Acid Amide ◽  
Chain Extender ◽  
New Material ◽  
Phase Separation Behavior ◽  
Separation Behavior ◽  
Ether Ester ◽  
Long Chain Branch ◽  
Chain Branch

As a means of developing new material for automobile weather-stripping and seal parts replacing the conventional ethylene propylene diene monomer rubber/polypropylene vulcanizate, a series of poly(ether ester) elastomers are synthesized. The hardness is modulated by controlling chain extender composition after fixing the hard segment to soft segment ratio. Targeted hardness is achieved by partly substituting conventional chain extender 1,4-butandiol for soybean oil-originated fatty acid amide diol that bears a long chain branch. The crystallinity and phase separation behavior resultant elastomer are also tunable simply by modulating chain extender composition and hard to soft segment ratio.

An experimental–numerical study on shape memory behavior of PU/PCL/ZnO ternary blend

2018 ◽  
Vol 30 (1) ◽  
pp. 116-126 ◽  
Author(s):  
M Abbasi-Shirsavar ◽  
M Baghani ◽  
M Taghavimehr ◽  
M Golzar ◽  
M Nikzad ◽  
...  
Keyword(s):  
Shape Memory ◽  
Polymer Composites ◽  
Zno Nanoparticles ◽  
Shape Recovery ◽  
Numerical Study ◽  
Soft Segment ◽  
Shape Memory Polymer ◽  
Ternary Blend ◽  
Recovery Ratio ◽  
Shape Memory Behavior

Shape memory polymer composites have attracted significant attention due to novel properties and great applications. In this article, we focus on the fabrication and simulation of polyurethane/polycaprolactone nanocomposites. The polyurethane/polycaprolactone blends containing ZnO nanoparticles (5 to 30 wt%) are fabricated using a solution mixing and casting method. It is found that significant improvement of polyurethane/polycaprolactone composites in Young’s modulus is achieved by incorporating 20 wt% of ZnO nanoparticles; also, the results of the shape recovery ratio reveal that adding an optimum amount of ZnO (the reinforcement) can increase the shape recovery ratio (for 20 wt% of ZnO). These results could most likely be explained by the fact that some particles restrict the hard segment–soft segment interactions and provide more mobility to polycaprolactone components, while the other nanoparticles can act as the nucleating agent for polycaprolactone chains. A generalized Maxwell model is then used to examine the shape memory behavior of shape memory polymer composites. The dynamic mechanical thermal analysis results are utilized to define the model coefficients and the simulation is carried out to determine the shape recovery ratio. Simulation of this shape recovery ratio for shape memory polymer composites reveals that the numerical results are in good agreement with those of the experimental data.

Effects of Ionic Group on the Shape Memory Performance of Polyurethane

2016 ◽  
Vol 848 ◽  
pp. 140-147
Author(s):  
Yan Ou Hu ◽  
Hui Qin Lian ◽  
Lei Zu ◽  
Yue Ting Li ◽  
Yang Liu ◽  
...  
Keyword(s):  
Shape Memory ◽  
Hard Segment ◽  
Soft Segment ◽  
Memory Performance ◽  
Average Molecular Weight ◽  
Phenyl Isocyanate ◽  
Exchange Capacity ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Hard Segment Content

Ionic polyurethane (IPU) was synthesized as shape memory materials. Poly (tetramethylene ether) glycol with 2000g/mol number average molecular weight were used as soft segment, 4,4-methylenebis (phenyl isocyanate), and 1,2-dihydroxy-3-propanesulfonic acid salt were used to compose the segment of SMP materials. The structure and properties of these IPU films were characterized by Fourier Transform infrared, X-ray diffraction, Thermal gravimetric analysis and Differential scanning calorimeter. The results showed that the glass transition temperature of the IPU increased with the increase of hard segment content. The physical properties in terms of swelling property, water absorption and ion-exchange capacity increased with the improving of sulfonic group content in IPU. The shape memory property of IPU exhibited that the shape fixity ratio and recovery rate improved remarkably with the increase of hard segment content.

The graft polymerization of vinyl benzoate and trans-stilbene onto polyurethane to control its mechanical and shape memory properties

2016 ◽  
Vol 88 (2) ◽  
pp. 121-132
Author(s):  
Yong-Chan Chung ◽  
Jin Cheol Bae ◽  
Byoung Chul Chun
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Shape Memory ◽  
Low Temperatures ◽  
Shape Recovery ◽  
Graft Polymerization ◽  
Control Series ◽  
Trans Stilbene ◽  
Shape Retention ◽  
Low Temperature Flexibility

Vinyl benzoate (VB series) and trans-stilbene (SB series) were added onto polyurethane (PU) via graft polymerization, and the spectroscopic, thermal, tensile, shape memory, and low-temperature flexibility properties of the resulting polymers were compared with those of unmodified PU. The melting temperature ( Tm) and glass transition temperature ( Tg) of the soft segments are not significantly different for the VB and SB series compared with unmodified PU. The tensile strengths of the VB and SB series sharply increase with increasing vinyl polymer content, whereas the control series does not exhibit an increase in tensile strength. The VB series exhibits excellent shape recovery at 10℃ compared with unmodified PU, and the shape recovery of the SB series remains above 90% at 45℃. The shape retention values of the VB (−45℃) and SB series (–25℃) are not less than 90%. The selected PUs demonstrate better flexibilities at extremely low temperatures compared with unmodified PU. Therefore, the graft polymerization of vinyl benzoate or trans-stilbene onto PU improves the tensile strength, shape recovery at low temperatures, and low-temperature flexibility of the polymer without decreasing the tensile strain or shape retention.

scholarly journals Study on carbon nanotube/shape memory polymer composites and their applications in wireless worm actuator

2021 ◽  
Vol 37 ◽  
pp. 636-650
Author(s):  
Wei-Hsuan Hsu ◽  
Chia-Wei Lin ◽  
Yi-Hung Chen ◽  
Shang-Ru Wu ◽  
Hung-Yin Tsai
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Carbon Nanotube ◽  
Reaction Time ◽  
Shape Memory ◽  
Polymer Composites ◽  
Microwave Heating ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Experimental Results

Abstract In this study, the surface of the carbon nanotubes was modified by chemical functionalization. The carbon nanotubes were placed in a mixed acid solution with a nitric acid-to-sulfuric acid volume ratio of 1:3. The results of the functionalization of the carbon nanotubes were investigated by controlling the reaction time. From the experimental results, the functionalized carbon nanotubes with a reaction time of 12 hours show good dispersibility. In the study of the essential characteristics of composite materials, it was observed that the tensile strength decreased with increase of carbon nanotube content. Compared with the result of the tensile strength test, it can be found that with increasing carbon nanotube content, the microwave heating and shape recovery speed are greatly improved. The experimental results show that the shape memory polymer composite with 4 wt% carbon nanotubes has the fastest microwave heating rate, so it takes only 2 minutes to achieve complete shape recovery. Finally, this study used shape memory polymer composites doped with 4 wt% carbon nanotubes as the driving end, combined with an elastic structure made of polyimide (PI) film using origami techniques to form a worm actuator. In the test, the system could move a distance of 6 mm forward during a microwave time of 1 minute. In addition, this research also constructed a physical model of shape memory polymer and explored the simple movement mechanism of the system.

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