Dopamine-Incorporated Dual Bioactive Electroactive Shape Memory Polyurethane Elastomers with Physiological Shape Recovery Temperature, High Stretchability, and Enhanced C2C12 Myogenic Differentiation

2017 ◽  
Vol 9 (35) ◽  
pp. 29595-29611 ◽  
Author(s):  
Xin Zhao ◽  
Ruonan Dong ◽  
Baolin Guo ◽  
Peter X. Ma
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Myogenic Differentiation ◽  
Polyurethane Elastomers ◽  
Shape Memory Polyurethane ◽  
Recovery Temperature

Surface characteristics of chitin-based shape memory polyurethane elastomers

2009 ◽  
Vol 72 (2) ◽  
pp. 248-252 ◽  
Author(s):  
Khalid Mahmood Zia ◽  
Mohammad Zuber ◽  
Mehdi Barikani ◽  
Ijaz Ahmad Bhatti ◽  
Mohammad Bilal Khan
Keyword(s):  
Shape Memory ◽  
Surface Characteristics ◽  
Polyurethane Elastomers ◽  
Shape Memory Polyurethane

Relationship between Annealing and Shape Memory Effect of Shape Memory Polyurethane

2014 ◽  
Vol 936 ◽  
pp. 140-144 ◽  
Author(s):  
Jia Ying ◽  
Masaaki Nishikawa ◽  
Masaki Hojo
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Length Change ◽  
Recovery Ratio ◽  
High Entropy ◽  
Change Of State ◽  
Relationship Of ◽  
Shape Memory Polyurethane

The relationship of annealing and shape memory effect of uniaxially oriented shape memory polyurethane was studied; meanwhile a new method of adjusting shape recovery ratio by annealing was proposed for further consideration. Experiments were designed to compare the influence on length change from annealing and shape memory effect with shape memory polyurethane film at 65°C. We found that for shape memory polyurethane which had residual strain from material processing procedure, annealing and shape memory effect have the same effect on its length change if they are both carried out at the same temperature. It is because annealing and shape memory effect have the same mechanism, which is the change of state from low conformational entropy states to the recovery of a stable high entropy state in the polymer. Moreover, it is proved by experiment that shape recovery ratio of shape memory polyurethane can be adjusted by annealing.

scholarly journals The Influence of Shape Changing Behaviors from 4D Printing through Material Extrusion Print Patterns and Infill Densities

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3754
Author(s):  
Seokwoo Nam ◽  
Eujin Pei
Keyword(s):  
Shape Memory ◽  
Recovery Time ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Material Extrusion ◽  
Concentric Pattern ◽  
Dimensional Printing ◽  
Recovery Result ◽  
Am Processes ◽  
Recovery Temperature

Four-dimensional printing (4DP) is an approach of using Shape Memory Materials (SMMs) with additive manufacturing (AM) processes to produce printed parts that can deform over a determined amount of time. This research examines how Polylactic Acid (PLA), as a Shape Memory Polymer (SMP), can be programmed by manipulating the build parameters of material extrusion. In this research, a water bath experiment was used to show the results of the shape-recovery of bending and shape-recovery speed of the printed parts, according to the influence of the print pattern, infill density and recovery temperature (Tr). In terms of the influence of the print pattern, the ‘Quarter-cubic’ pattern with a 100% infill density showed the best recovery result; and the ‘Line’ pattern with a 20% infill density showed the worst recovery result. The ‘Cubic-subdivision’ pattern with a 20% infill density demonstrated the shortest recovery time; and the ‘Concentric’ pattern with a 100% infill density demonstrated the longest recovery time. The results also showed that a high temperature and high infill density provided better recovery, and a low temperature and low infill density resulted in poor recovery.

scholarly journals Shape Memory Polyurethane Biocomposites Based on Toughened Polycaprolactone Promoted by Nano-Chitosan

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 225 ◽  
Author(s):  
Arvind Gupta ◽  
Beom Soo Kim
Keyword(s):  
Shape Memory ◽  
Biomedical Applications ◽  
Shape Recovery ◽  
Permanent Deformation ◽  
Testing Machine ◽  
Microscopic Analysis ◽  
Original Form ◽  
Electron Microscopic ◽  
Unique Shape ◽  
Shape Memory Polyurethane

The distinctive ability to remember their original form after partial or complete deformation makes shape memory polymers remarkable materials for several engineering and biomedical applications. In the present work, the development of a polycaprolactone based toughened shape memory polyurethane biocomposite promoted by in situ incorporation of chitosan flakes has been demonstrated. The chitosan flakes were homogeneously present in the polymer matrix in the form of nanoflakes, as confirmed by the electron microscopic analysis and probably developed a crosslinked node that promoted toughness (a > 500% elongation at break) and led to a ~130% increment in ultimate tensile strength, as analyzed using a universal testing machine. During a tensile pull, X-ray analysis revealed the development of crystallites, which resulted from a stress induced crystallization process that may retain the shape and melting of the crystallites stimulating shape recovery (with a ~100% shape recovery ratio), even after permanent deformation. The biodegradable polyurethane biocomposite also demonstrates relatively high thermal stability (Tmax at ~360 °C). The prepared material possesses a unique shape memory behavior, even after permanent deformation up to a > 500% strain, which may have great potential in several biomedical applications.

Manufacturing of a Shape Memory Polymer Actuator

2015 ◽  
Author(s):  
Loredana Santo ◽  
Giovanni Matteo Tedde ◽  
Fabrizio Quadrini
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Active Element ◽  
Shape Memory Polymer ◽  
Applied Pressure ◽  
Maximum Load ◽  
Medium Size ◽  
Cylindrical Shape ◽  
Polymer Actuator ◽  
Recovery Temperature

Shape memory polymer (SMP) foams can be used to manufacture actuators with tailored actuation rate. Being related to foam shape recovery by heating, SMP actuator operates by conversion of heat into motion. In the current study, a SMP linear actuator has been manufactured which is able to apply a maximum load of 50 N (depending on the recovery temperature) and a maximum stroke up to 30 mm. The actuator had a cylindrical shape and its piston had a diameter of 16 mm, therefore a maximum applied pressure about 2.5 bar. The active element (i.e. SMP foam) was produced by solid state foaming of an epoxy resin, and its shaping was performed in the same metallic frame of the actuator. Results show that small and medium-size actuators can be easily produced and operated.

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.

Grafting of shape memory polyurethane with poly(ethyleneimine) and the effect on electrolytic attraction in aqueous solution and shape recovery properties

2011 ◽  
Vol 20 (1) ◽  
pp. 66-75 ◽  
Author(s):  
Yong-Chan Chung ◽  
Jong Shin Park ◽  
Chang Hoon Shin ◽  
Jae Won Choi ◽  
Byoung Chul Chun
Keyword(s):  
Aqueous Solution ◽  
Shape Memory ◽  
Shape Recovery ◽  
Shape Memory Polyurethane

scholarly journals Nanoclay Modification of Shape Memory Polyurethane

2015 ◽  
Vol 15 (4) ◽  
pp. 327
Author(s):  
J. Dyana Merline ◽  
Reghunadhan Nair, C.P.
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Clay Content ◽  
Bending Test ◽  
Modulus Ratio ◽  
Tem Analysis ◽  
Shape Memory Property ◽  
Nanoclay Content ◽  
Shape Memory Polyurethane ◽  
Memory Characteristics

Effect of nanoclay modification on the properties of  polytetramethylene oxide-based polyurethane was examined. Nanoclay was dispersed in polyurethane wherein the clay content was varied from 1 to 5 wt.%. The nanocomposites were characterized by thermal, FTIR, XRD and thermo-mechanical analyses and their shape memory properties were evaluated. Morphology was examined by TEM analysis. Bending test<br />was adopted for the evaluation of shape memory property. Increase in clay content resulted an increase in transition temperature. Tensile strength and modulus increased proportional to nanoclay content. The elongation decreased with clay content. Intercalated structure of clay in the PU matrix was observed<br />from XRD studies, which was confirmed by TEM analysis. Modulus ratio showed a decreasing trend with nanoclay content. This resulted in decreased shape recovery characteristics. Highest shape recovery of 92% was observed for PU with 1 wt.% clay content. Moderate nanoclay leveling is conducive to deriving<br />mechanically stronger PU without loss of shape memory characteristics.

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