Effects of graphene nanoplatelets on bio-based shape memory polymers from benzoxazine/epoxy copolymers actuated by near-infrared light

2021 ◽  
pp. 1045389X2110235
Author(s):  
Surapong Srisaard ◽  
Lunjakorn Amornkitbamrung ◽  
Krittapas Charoensuk ◽  
Chaweewan Sapcharoenkun ◽  
Chanchira Jubsilp ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Near Infrared ◽  
Shape Memory Polymers ◽  
Graphene Nanoplatelets ◽  
Dynamic Mechanical ◽  
Nir Light ◽  
Uniform Dispersion ◽  
Shape Memory Properties ◽  
Shape Fixity

Novel near-infrared (NIR) light-induced bio-based shape memory polymers (SMPs) were prepared from copolymers of vanillin/furfurylamine-based benzoxazine monomer (V-fa monomer) and epoxidized castor oil (ECO). Incorporation of graphene nanoplatelets (GNPs) as photothermal fillers into the copolymers provided shape memory properties under near-infrared (NIR) light actuation. The effects of GNP content on photothermal, thermal, dynamic mechanical, morphology, and shape memory properties of the bio-based benzoxazine/epoxy copolymers (V-fa/ECO copolymers) were investigated. The results showed that the addition of GNPs significantly improved the photothermal, thermal, and dynamic mechanical properties of the copolymers. The uniform dispersion of 3 wt% GNPs in the V-fa/ECO copolymers resulted in the highest shape memory performance with shape fixity of 92% and shape recovery of 99% upon NIR light actuation. The recovery time decreased with the increment of GNP content, and the V-fa/ECO copolymers filled with GNPs displayed good execution in the repeated fold-deploy, in which the shape fixity and shape recovery values were close to the original specimen. Therefore, the outstanding properties of V-fa/ECO copolymers filled with GNPs had a potential to be excellent SMPs under NIR actuation.

scholarly journals Effect of PEW and CS on the Thermal, Mechanical, and Shape Memory Properties of UHMWPE

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 483
Author(s):  
Run Zhang ◽  
Suwei Wang ◽  
Jing Tian ◽  
Ke Chen ◽  
Ping Xue ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Shape Memory Polymers ◽  
Effect Of Temperature ◽  
Comprehensive Performance ◽  
Shape Memory Properties ◽  
Polyethylene Wax ◽  
Entanglement Network ◽  
Ultra High Molecular Weight ◽  
Shape Fixity

Modified ultra-high-molecular-weight polyethylene (UHMWPE) with calcium stearate (CS) and polyethylene wax (PEW) is a feasible method to improve the fluidity of materials because of the tense entanglement network formed by the extremely long molecular chains of UHMWPE, and a modified UHMWPE sheet was fabricated by compression molding technology. A Fourier-transform infrared spectroscopy test found that a new chemical bond was generated at 1097 cm−1 in the materials. Besides, further tests on the thermal, thermomechanical, mechanical, and shape memory properties of the samples were also conducted, which indicates that all properties are affected by the dimension and distribution of crystal regions. Moreover, the experimental results indicate that the addition of PEW and CS can effectively improve the mechanical properties. Additionally, the best comprehensive performance of the samples was obtained at the PEW content of 5 wt % and the CS content of 1 wt %. In addition, the effect of temperature on the shape memory properties of the samples was investigated, and the results indicate that the shape fixity ratio (Rf) and the shape recovery ratio (Rr) can reach 100% at 115 °C and 79% at 100 °C, respectively, which can contribute to the development of UHMWPE-based shape memory polymers.

Preparation of porous structures with shape memory properties from biodegradable polymeric networks

2012 ◽  
Vol 1403 ◽  
Author(s):  
Shahriar Sharifi ◽  
Sebastien Blanquer ◽  
Dirk W. Grijpma
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Soft Tissues ◽  
Shape Memory Polymers ◽  
Porous Structures ◽  
Trimethylene Carbonate ◽  
Polymeric Networks ◽  
Shape Memory Properties ◽  
Crosslinked Networks ◽  
Shape Fixity

ABSTRACTPreparing porous biodegradable structures from shape memory polymers can combine the structure-defining properties of porous structures with the minimally invasive implanting possibilities of shape memory polymers. In this study, porous biodegradable shape memory structures were prepared using photo-crosslinked networks based on poly(D,L-lactide-co-trimethylene carbonate). The characteristic shape memory properties of the structures, such as their shape fixity at a low temperature of 0 oC and their full shape recovery upon heating to physiological temperatures, were excellent. This makes these biodegradable and biocompatible structures very well-suited for use as self-deploying implants in medical applications like tissue engineering, drug delivery and the support of soft tissues.

Synthesis, structure and tunable shape memory properties of polytriazoles: dual-trigger temperature and repeatable shape recovery

2015 ◽  
Vol 3 (21) ◽  
pp. 11596-11606 ◽  
Author(s):  
M. Ragin Ramdas ◽  
K. S. Santhosh Kumar ◽  
C. P. Reghunadhan Nair
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Shape Memory Polymers ◽  
Shape Memory Properties

Click assisted synthesis resulted in low, high and dual trigger temperature shape memory polymers. They exhibit high shape recovery and repeatability in shape memory properties.

scholarly journals The Influence of Water and Solvent Uptake on Functional Properties of Shape-Memory Polymers

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Ehsan Ghobadi ◽  
Axel Marquardt ◽  
Elias Mahmoudinezhad Zirdehi ◽  
Klaus Neuking ◽  
Fathollah Varnik ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Shape Memory Polymers ◽  
Holding Time ◽  
Fickian Diffusion ◽  
Recovery Ratio ◽  
Solvent Uptake ◽  
Time Shape ◽  
Influence Of Water ◽  
Shape Fixity

In this contribution, diffusion of water, acetone, and ethanol into a polymer matrix has been studied experimentally and numerically by finite element approaches. Moreover, the present study reports an assessment of different thermomechanical conditions of the shape-memory (SM) performance, for example, stress- or strain-holding times in stress- or strain-controlled thermomechanical cycles and the effect of maximum strain. According to the results presented here, the uptake of acetone in Estane is much higher than ethanol and follows classical Fickian diffusion. Further, a series of thermomechanical measurements conducted on dry and physically (hydrolytically) aged polyether urethanes revealed that incorporation of water seems to have an appreciable impact on the shape recovery ratios which can be attributed to the additional physical crosslinks. However, no obvious difference in shape fixation of dry and physically (hydrolytically) aged samples could be recognized. Furthermore, by decreasing the strain-holding time, shape recovery improves significantly. Moreover, the shape fixity is found to be independent of holding time. The shape recovery ratio decreased dramatically with an increase in the stress-holding time.

High-Strain Shape-Memory Properties of Poly(Carbonate-Urea-Urethane)s Based on Aliphatic Oligocarbonates and L-Lysine Diisocyanate

MRS Advances ◽  
2017 ◽  
Vol 2 (47) ◽  
pp. 2529-2536
Author(s):  
Magdalena Mazurek-Budzyńska ◽  
Muhammad Y. Razzaq ◽  
Gabriel Rokicki ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Shape Memory ◽  
Medical Devices ◽  
Shape Recovery ◽  
High Strain ◽  
Shape Memory Polymers ◽  
Interesting Candidate ◽  
Degradable Biomaterials ◽  
Precursor Route ◽  
Shape Fixity ◽  
Poly Carbonate

ABSTRACTThe simultaneous capability of high-strain deformation and high shape recovery ratio constitutes a great challenge in design of the shape-memory polymers. Here we report on poly(carbonate-urea-urethane)s (PCUUs) synthesized by a precursor route, based on oligo(alkylene carbonate) diols, L-lysine diisocyanate (LDI), and water vapor. When programed with a strain of εprog = 800%, the PCUU networks exhibited a one-way shape-memory effect (1W-SME) with excellent shape fixity (> 97%) and shape recovery (> 99%) ratios. The switching temperatures (Tsw) varied between 50 and 56 °C and correlated to the melting transitions of the switching domains. The obtained PCUUs capable of high-strain are interesting candidate materials for degradable biomaterials as required in smart medical devices.

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.

Shape Memory Properties of Ti-Ni Shape Memory Alloy / Shape Memory Polymer Composites Using Additive Manufacturing

2021 ◽  
Vol 1016 ◽  
pp. 697-701
Author(s):  
Kazuhiro Kitamura
Keyword(s):  
Shape Memory ◽  
Transformation Temperature ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
The Other ◽  
3D Printer ◽  
Shape Memory Material ◽  
Polymer Resin ◽  
Shape Memory Properties

Shape memory alloys (SMAs) have the disadvantage that cooling is difficult and the actuating speed during cooling is slow. To resolve this problem, shape memory material actuators that operate only with heating is required. SMAs are characterized by a low apparent Young's modulus below the transformation temperature and a strong shape recovery force above the reverse transformation temperature. Alternatively, shape memory polymers (SMPs) have two properties: shape fixability and shape recovery. The SMPs are hardened below the glass transition (Tg) temperature and the material is recovered to memorized shape above the Tg temperature. The other hand, 3D printer is a machine that can directly output a 3D-designed product designed by a computer in 3D, and molded materials such as polymer, resin, metal, and ceramics. In this research, we developed the SMC of SMA wire and SMP sheet using adhesive that develops actuates into two shapes only by heating.

Shape-Memory Properties of Electrospun Non-wovens Prepared from Amorphous Polyetherurethanes Under Stress-free and Constant Strain Conditions

2012 ◽  
Vol 1403 ◽  
Author(s):  
Tilman Sauter ◽  
Karl Kratz ◽  
Andreas Lendlein
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Fiber Diameter ◽  
Tensile Tests ◽  
Polymer Chains ◽  
Single Fiber ◽  
Elongation At Break ◽  
Shape Memory Properties ◽  
Degree Of Orientation ◽  
Shape Fixity

ABSTRACTThe shape-memory properties of electrospun polyetherurethanes (PEU) non-wovens with a single fiber diameter of around 1 μm were explored. In uniaxial cyclic, thermomechanical tensile tests a dual-shape shape-memory creation procedure (SMCP) was applied and the shape recovery was examined under stress-free and constant strain conditions. The thermal properties of the electrospun PEU non-wovens were found to be similar to those obtained for bulk PEU samples, whereas the mechanical properties revealed differences with respect to the elongation at break (εb) at increased temperatures. Excellent dual-shape properties were achieved for the PEU non-wovens with a high shape fixity rate (Rf) and shape recovery rate (Rr). A significant higher recovery stress (σmax) was obtained under constant strain recovery conditions for the electrospun non-wovens compared to the bulk PEU samples, which might be attributed to the higher degree of orientation of the polymer chains in the microfibers. Therefore the influence of different (single) fiber diameters as well as the variation of the programming elongation εm and temperature Tprog on σmax is an interesting issue for future investigations.

Shape-Memory Properties of Nanocomposites based on Poly(ω-pentadecalactone) and Magnetic Nanoparticles

2012 ◽  
Vol 1403 ◽  
Author(s):  
M. Y. Razzaq ◽  
M. Behl ◽  
A. Lendlein
Keyword(s):  
Mechanical Properties ◽  
Magnetic Nanoparticles ◽  
Shape Memory ◽  
Shape Recovery ◽  
Weight Content ◽  
Magnetic Heating ◽  
Shape Memory Properties ◽  
Potential Applications ◽  
Alternating Magnetic Fields ◽  
Shape Fixity

ABSTRACTMagneto-sensitive shape-memory polymers (SMP) obtained by incorporating magnetic nanoparticles in a SMP matrix are an emerging class of multifunctional materials. The incorporation of the nanoparticles enhanced the mechanical properties and in addition enabled remote actuation by exposure to alternating magnetic fields. Here, we report on the thermallyinduced shape-memory properties of such magneto-sensitive nanocomposites based on poly(ω- pentadecalactone) (PPDL) switching segments and magnetic nanoparticles. A series of nanocomposites were prepared by crosslinking of poly(ω-pentadecalactone)dimethacrylate (Mn = 2800 g·mol-1and 5100 g·mol-1) in the presence of silica encapsulated magnetic nanoparticles. The silica shell of the nanoparticles was selected to enhance the distribution and compatibility of the nanoparticles with the polymer matrix. Thermal and mechanical properties of the nanocomposites were explored as a function of PPDL chain length and nanoparticle weight content. All nanocomposites exhibited excellent shape-memory properties with shape fixity rates between 86% and 93% and shape recovery rates above 97%. Potential applications for such shape-memory nanocomposites include smart implants, medical instruments, which could be controlled on demand by thermal or indirect magnetic heating.

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