Facile fabrication of a well-defined poly(p-dioxanone) dynamic network from metallosupramolecular interactions to obtain an excellent shape-memory effect

A novel poly(p-dioxanone) dynamic network was fabricated from metallosupramolecular interactions via an elaborate synthetic strategy which shows excellent shape-memory performance.

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A Facile Fabrication of PCL/OBC/MWCNTs Nanocomposite with Selective Dispersion of MWCNTs to Access Electrically Responsive Shape Memory Effect

Polymer Composites ◽

10.1002/pc.24996 ◽

2018 ◽

Vol 40 (S2) ◽

pp. E1353-E1363 ◽

Cited By ~ 2

Author(s):

Zi‐Xuan Yang ◽

Xu Liu ◽

Yan Shao ◽

Bo Yin ◽

Ming‐Bo Yang

Keyword(s):

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Facile Fabrication

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Shape Memory Behavior of Rapidly Quenched High-copper TiNiCu Alloys

U Porto Journal of Engineering ◽

10.24840/2183-6493_007.002_0002 ◽

2021 ◽

Vol 7 (2) ◽

pp. 2-10

Author(s):

Alexander Shelyakov ◽

Nikolay Sitnikov ◽

Irina Khabibullina ◽

Kirill Borodako ◽

Oleg Sevryukov

Keyword(s):

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Copper Content ◽

Electric Pulse ◽

Memory Performance ◽

Annealing Duration ◽

Special Importance ◽

High Copper ◽

Melt Cooling

Rapidly quenched quasibinary TiNi–TiCu system alloys with high copper contents (above 20 at.%) exhibit excellent shape memory effect and have considerably narrower hysteresis as compared with the TiNi binary alloy, this advantage being of special importance for cyclic load applications, e.g. for microelectromechanics (MEMS). The aim of this work is to study the effect of annealing parameters and copper content on the shape memory effect in TiNiCu alloys. Thin amorphous ribbons of TiNi-TiCu alloys with copper contents of 25 to 40 at.% were produced by planar flow casting at a melt cooling rate of about 106 K/s. The alloys were crystallized by isothermal annealing with variable duration and by exposing specimens to a short (10 ms) electric pulse. Increasing the copper content to above 30 at.% considerably reduces the plasticity and shape memory effect of the alloys. However, significant reduction of annealing duration greatly improves the shape memory performance due to prevention of the formation of brittle Ti-Cu phases in the alloys structure.

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Vitrimer-Like Shape Memory Polymers: Characterization and Applications in Reshaping and Manufacturing

Polymers ◽

10.3390/polym12102330 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2330

Author(s):

Tao Xi Wang ◽

Hong Mei Chen ◽

Abhijit Vijay Salvekar ◽

Junyi Lim ◽

Yahui Chen ◽

...

Keyword(s):

Solid State ◽

3D Printing ◽

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Memory Performance ◽

Shape Memory Polymers ◽

Cross Linking ◽

Potential Applications ◽

Actual Shape

The shape memory effect (SME) refers to the ability of a material to recover its original shape, but only in the presence of a right stimulus. Most polymers, either thermo-plastic or thermoset, can have the SME, although the actual shape memory performance varies according to the exact material and how the material is processed. Vitrimer, which is between thermoset and thermo-plastic, is featured by the reversible cross-linking. Vitrimer-like shape memory polymers (SMPs) combine the vitrimer-like behavior (associated with dissociative covalent adaptable networks) and SME, and can be utilized to achieve many novel functions that are difficult to be realized by conventional polymers. In the first part of this paper, a commercial polymer is used to demonstrate how to characterize the vitrimer-like behavior based on the heating-responsive SME. In the second part, a series of cases are presented to reveal the potential applications of vitrimer-like SMPs and their composites. It is concluded that the vitrimer-like feature not only enables many new ways in reshaping polymers, but also can bring forward new approaches in manufacturing, such as, rapid 3D printing in solid state on space/air/sea missions.

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Influence of Radialization Dosage on Shape Memory Effect of Polystyrene Copolymer

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.47-50.690 ◽

2008 ◽

Vol 47-50 ◽

pp. 690-693 ◽

Cited By ~ 2

Author(s):

Da Wei Zhang ◽

Jin Song Leng ◽

Yan Ju Liu

Keyword(s):

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Smart Materials ◽

Shape Recovery ◽

Memory Performance ◽

Shape Memory Polymer ◽

Shape Memory Polymers ◽

Mechanical Analysis ◽

Styrene Copolymer

This paper is concerned about the synthesis of shape memory styrene copolymer and the investigation of the influence of radialization dosage on its shape memory effect. As one of novel actuators in smart materials, shape memory polymers (SMPs) have been investigated intensively. Styrene copolymer with proper cross-linking degree can exhibit shape memory effect (SME). In this paper, the influence of radialization on shape memory effect of styrene copolymer was investigated through altering the dosage of radialization. The radialization dosage of styrene copolymer was determined by changed radicalization time. The glass transition temperature (Tg) of styrene copolymerwas measured by Dynamic Mechanical Analysis (DMA). The shape memory performance of styrene copolymer with different radiated dosage was also evaluated. Results indicated that the shape memory polymer (SMP) was synthesized successfully. The Tg increased from 60°C to 65°C followed by increasing the radialization dosage. Moreover, the SMP experienced good SME and the largest reversible strain of the SMP reached as high as 150%. When heating above Tg+30°C (different copolymers performed different Tg), the shape recovery speed of the copolymers increased with increasing the radialization dosage. However, the recovery speed decreased with increasing the radialization dosage at the same temperature of 95°C.

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Influence of Compression Direction on the Shape-Memory Effect of Micro-Cylinder Arrays Prepared from Semi-Crystalline Polymer Networks

MRS Advances ◽

10.1557/adv.2016.389 ◽

2016 ◽

Vol 1 (27) ◽

pp. 1985-1993 ◽

Cited By ~ 9

Author(s):

Yi Jiang ◽

Liang Fang ◽

Karl Kratz ◽

Andreas Lendlein

Keyword(s):

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Shape Recovery ◽

Shape Change ◽

Memory Performance ◽

Polymer Networks ◽

Crystalline Polymer ◽

Complete Recovery ◽

Compression Direction

ABSTRACTMicrostructured polymeric surfaces capable of a thermally-induced shape-memory effect (SME) can perform on demand changes of surface properties such as wettability or adhesion.In this study, we explored the influence of the applied compression direction during programming, i.e. vertical compression and tilted compression, on the SME of microstructured crosslinked poly[ethylene-co-(vinyl acetate)] (cPEVA) films comprising arrays of micro-cylinders with a height of 10 µm and different diameters of 10 µm, 25 µm, and 50 µm. The shape recovery of the microstructures during heating was visualized online by optical microscopy, while atomic force microscopy (AFM) was utilized to investigate the temperature-induced shape change of single micro-cylinders. Here, the changes in micro-cylinder height and the characteristic angle θ were followed and analyzed for quantification of the shape-memory performance. Both compression modes resulted in almost flat programmed surfaces as indicated by high shape fixity ratios of Rf ≥ 93±1%. A nearly complete recovery of the micro-cylinders was obtained for all investigated cPEVA samples documented by high shape recovery values of Rr ≥ 97±1%, while the obtained shape change of the micro-cylinders during recovery almost reversely recalled the applied deformation during programming. The presented capability of SMP microstructured substrates to memorize the way of deformation during programming could be a new tool for controlling particular shape changes of microstructures during recovery and in such a way the generated local recovery forces can be adjusted.

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Tensile Failure of 55-Nitinol Wire

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100113858 ◽

1975 ◽

Vol 33 ◽

pp. 46-47

Author(s):

F. I. Grace

Keyword(s):

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Stoichiometric Composition ◽

Tensile Failure ◽

Initial State ◽

Initial Shape ◽

Nitinol Wire ◽

Cscl Type ◽

Shear Transformation

An interest in NiTi alloys with near stoichiometric composition (55 NiTi) has intensified since they were found to exhibit a unique mechanical shape memory effect at the Naval Ordnance Laboratory some twelve years ago (thus refered to as NITINOL alloys). Since then, the microstructural mechanisms associated with the shape memory effect have been investigated and several interesting engineering applications have appeared.The shape memory effect implies that the alloy deformed from an initial shape will spontaneously return to that initial state upon heating. This behavior is reported to be related to a diffusionless shear transformation which takes place between similar but slightly different CsCl type structures.

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