scholarly journals Isocyanate Modified GO Shape-Memory Polyurethane Composite

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 118 ◽  
Author(s):  
Yuanchi Zhang ◽  
Jinlian Hu
Keyword(s):  
Graphene Oxide ◽  
Minimally Invasive ◽  
Shape Memory ◽  
Bone Repair ◽  
Recovery Process ◽  
Invasive Treatment ◽  
Element Analysis ◽  
Polyurethane Composite ◽  
Shape Memory Effects ◽  
Shape Memory Polyurethane

Shape-memory composites have benefits for minimally invasive surgery, but their wider applications for bone repair are hindered by conflicts between the mechanical and memory performances, especially at load-bearing locations. In this study, we fabricated a graphene oxide shape-memory polyurethane composite through the chemical combination of graphene oxide and isocyanate, in order to realize satisfactory mechanical and shape-memory effects. As desired, a modulus of ~339 MPa and a shape recovery ratio of 98% were achieved, respectively, in the composite. In addition, finite element analysis demonstrated that, after being implanted in a defective bone through a minimally invasive treatment, where the highest stress was distributed at the implant–bone interface, this composite could offer a generated force during the recovery process. Furthermore, we also discuss the origins of the improved mechanical and memory properties of the composites, which arise from increased net-points and the stable molecular structure inside. Therefore, with its superior structure and properties, we envision that this shape-memory composite can provide new insights toward the practical application of shape-memory polymers and composites in the field of bone repair.

Mechanically Robust Shape Memory Polyurethane Nanocomposites for Minimally Invasive Bone Repair

2019 ◽  
Vol 2 (3) ◽  
pp. 1056-1065 ◽  
Author(s):  
Yuanchi Zhang ◽  
Jinlian Hu ◽  
Xin Zhao ◽  
Ruiqi Xie ◽  
Tingwu Qin ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Shape Memory ◽  
Bone Repair ◽  
Shape Memory Polyurethane ◽  
Polyurethane Nanocomposites

Characterization of Flexibly Linked Shape Memory Polyurethane Composite with Magnetic Property

2011 ◽  
Vol 25 (3) ◽  
pp. 283-303 ◽  
Author(s):  
Yong-Chan Chung ◽  
Jae Won Choi ◽  
Min Woo Choi ◽  
Byoung Chul Chun
Keyword(s):  
Magnetic Property ◽  
Shape Memory ◽  
Polyurethane Composite ◽  
Shape Memory Polyurethane

Multifunctional composite nanofibers with shape memory and piezoelectric properties for energy harvesting

2020 ◽  
Vol 31 (7) ◽  
pp. 956-966 ◽  
Author(s):  
Xiaoyu Guan ◽  
Hairong Chen ◽  
Hong Xia ◽  
Yaqin Fu ◽  
Yiping Qiu ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Shape Memory ◽  
Lead Zirconate Titanate ◽  
Composite Nanofibers ◽  
Piezoelectric Materials ◽  
Lead Zirconate ◽  
Silane Coupling Agents ◽  
Zirconate Titanate ◽  
Shape Memory Effects ◽  
Shape Memory Polyurethane

Although many kinds of flexible piezoelectric materials have been developed, there were few reports on flexible multifunctional nanofibers for energy harvesting. In this study, we prepared multifunctional nanofibers from lead zirconate titanate particles and shape memory polyurethane by electrospinning. The resulting nanofibers had both piezoelectric and shape memory effects. To improve the dispersion, lead zirconate titanate particles were modified by silane coupling agents. The lead zirconate titanate/shape memory polyurethane nanofibers were used to harvest energy from sinusoidal vibrations, and the lead zirconate titanate 80 wt% sample produced voltages of 120.3 mV (peak-to-peak). Taking advantage of the shape memory effect, the lead zirconate titanate/shape memory polyurethane nanofibers can be easily deformed into desired shapes and revealed the potential for realizing energy harvesting in complex structures.

scholarly journals Multiwalled Carbon Nanotube Reinforced Bio-Based Benzoxazine/Epoxy Composites with NIR-Laser Stimulated Shape Memory Effects

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 881 ◽  
Author(s):  
Wassika Prasomsin ◽  
Tewarak Parnklang ◽  
Chaweewan Sapcharoenkun ◽  
Sunan Tiptipakorn ◽  
Sarawut Rimdusit
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Recovery Process ◽  
Memory Effects ◽  
Molecular Characteristics ◽  
Multiwalled Carbon ◽  
Dynamic Mechanical ◽  
Good Shape ◽  
Shape Memory Effects ◽  
Nir Laser

Smart materials with light-actuated shape memory effects are developed from renewable resources in this work. Bio-based benzoxazine resin is prepared from vanillin, furfurylamine, and paraformaldehyde by utilizing the Mannich-like condensation. Vanillin-furfurylamine-containing benzoxazine resin (V-fa) is subsequently copolymerized with epoxidized castor oil (ECO). When the copolymer is reinforced with multiwalled carbon nanotubes (MWCNTs), the resulting composite exhibits shape memory effects. Molecular characteristics of V-fa resin, ECO, and V-fa/ECO copolymers are obtained from Fourier transform infrared (FT-IR) spectroscopy. Curing behavior of V-fa/ECO copolymers is investigated by differential scanning calorimetry. Dynamic mechanical properties of MWCNT reinforced V-fa/ECO composites are determined by dynamic mechanical analysis. Morphological details and distribution of MWCNTs within the copolymer matrix are characterized by transmission electron microscopy. Shape memory performances of MWCNT reinforced V-fa/ECO composites are studied by shape memory tests performed with a universal testing machine. After a significant deformation to a temporary shape, the composites can be recovered to the original shape by near-infrared (NIR) laser actuation. The shape recovery process can be stimulated at a specific site of the composite simply by focusing NIR laser to that site. The shape recovery time of the composites under NIR actuation is four times faster than the shape recovery process under conventional thermal activation. Furthermore, the composites possess good shape fixity and good shape recovery under NIR actuation.

scholarly journals Preparation and Characterization of an Injectable and Photo-Responsive Chitosan Methacrylate/Graphene Oxide Hydrogel: Potential Applications in Bone Tissue Adhesion and Repair

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 126
Author(s):  
Daniela N. Céspedes-Valenzuela ◽  
Santiago Sánchez-Rentería ◽  
Javier Cifuentes ◽  
Mónica Gantiva-Diaz ◽  
Julian A. Serna ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Bone Tissue ◽  
Bone Repair ◽  
Medical Community ◽  
Element Analysis ◽  
Biological Assays ◽  
Femur Fractures ◽  
Potential Applications ◽  
Fea Simulation

As life expectancy continues to increase, the inevitable weakening and rupture of bone tissue have grown as concerns in the medical community, thus leading to the need for adhesive materials suitable for bone repair applications. However, current commercially available adhesives face certain drawbacks that prevent proper tissue repair, such as low biocompatibility, poor adhesion to wet surfaces, and the need for high polymerization temperatures. This work aims to develop an injectable and photo-responsive chitosan methacrylate/graphene oxide (ChiMA/GO) adhesive nanocomposite hydrogel of high biocompatibility that is easy to apply by simple extrusion and that offers the possibility for in situ polymer and physiological temperatures. The nanocomposite was thoroughly characterized spectroscopically, microscopically, rheologically, thermally, and through mechanical, textural, and biological assays to fully evaluate its correct synthesis and functionalization and its performance under physiological conditions that mimic those observed in vivo. In addition, a finite element analysis (FEA) simulation was used to evaluate its performance in femur fractures. Results suggest the material’s potential as a bioadhesive, as it can polymerize at room temperature, shows superior stability in physiological media, and is capable of withstanding loads from body weight and movement. Moreover, the material showed remarkable biocompatibility as evidenced by low hemolytic and intermediate platelet aggregation tendencies, and high cytocompatibility when in contact with osteoblasts. The comprehensive studies presented here strongly suggest that the developed hydrogels are promising alternatives to conventional bone adhesives that might be further tested in vivo in the near future.

scholarly journals Effects of Sterilization on Shape Memory Polyurethane Embolic Foam Devices

2017 ◽  
Vol 11 (3) ◽  
Author(s):  
Rachael Muschalek ◽  
Landon Nash ◽  
Ryan Jones ◽  
Sayyeda M. Hasan ◽  
Brandis K. Keller ◽  
...  
Keyword(s):  
Electron Beam ◽  
Minimally Invasive ◽  
Shape Memory ◽  
Medical Devices ◽  
Biomedical Applications ◽  
Shape Memory Polymer ◽  
Thermal Characterization ◽  
Device Fabrication ◽  
Shape Memory Polyurethane

Polyurethane shape memory polymer (SMP) foams have been developed for various embolic medical devices due to their unique properties in minimally invasive biomedical applications. These polyurethane materials can be stored in a secondary shape, from which they can recover their primary shape after exposure to an external stimulus, such as heat and water exposure. Tailored actuation temperatures of SMPs provide benefits for minimally invasive biomedical applications, but incur significant challenges for SMP-based medical device sterilization. Most sterilization methods require high temperatures or high humidity to effectively reduce the bioburden of the device, but the environment must be tightly controlled after device fabrication. Here, two probable sterilization methods (nontraditional ethylene oxide (ntEtO) gas sterilization and electron beam irradiation) are investigated for SMP medical devices. Thermal characterization of the sterilized foams indicated that ntEtO gas sterilization significantly decreased the glass transition temperature. Further material characterization was undertaken on the electron beam (ebeam) sterilized samples, which indicated minimal changes to the thermomechanical integrity of the bulk foam and to the device functionality.

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