Influence of Radialization Dosage on Shape Memory Effect of Polystyrene Copolymer

2008 ◽  
Vol 47-50 ◽  
pp. 690-693 ◽  
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.

Study on Shape Recovery Behaviors of Epoxy-Based Shape Memory Polymer

2011 ◽  
Vol 179-180 ◽  
pp. 325-328 ◽  
Author(s):  
Bo Zhou ◽  
Xue Lian Wu ◽  
Yan Ju Liu ◽  
Jin Song Leng
Keyword(s):  
Glass Transition ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Numerical Calculations ◽  
Glass Transition Temperatures ◽  
Recovery Experiment

The glass transition temperatures of epoxy-based shape memory polymers (SMPs), which contain a flexibilizer at various contents of 0%, 5%, 10% and 15% respectively, are determined through DMA tests. The shape memory effect of such materials is investigated through shape recovery experiments. Experimental results show that the content of flexibilizer has much influence on the shape memory effect of epoxy-based SMP. A shape recovery equation is developed based on the results of shape recovery experiment. Numerical calculations show that the developed shape recovery equation well predicts the shape recovery behaviors of epoxy-based SMP.

scholarly journals Bio-Based Epoxy Shape-Memory Thermosets from Triglycidyl Phloroglucinol

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 542 ◽  
Author(s):  
David Santiago ◽  
Dailyn Guzmán ◽  
Francesc Ferrando ◽  
Àngels Serra ◽  
Silvia De la Flor
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Memory Performance ◽  
Crosslinking Agent ◽  
Shape Memory Polymers ◽  
Crosslinking Density ◽  
Mechanical Analysis ◽  
Diglycidyl Ether ◽  
Partial Substitution ◽  
Scanning Calorimetry

A series of bio-based epoxy shape-memory thermosetting polymers were synthesized starting from a triglycidyl phloroglucinol (3EPOPh) and trimethylolpropane triglycidyl ether (TPTE) as epoxy monomers and a polyetheramine (JEF) as crosslinking agent. The evolution of the curing process was studied by differential scanning calorimetry (DSC) and the materials obtained were characterized by means of DSC, thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), stress-strain tests, and microindentation. Shape-memory properties were evaluated under free and totally constrained conditions. All results were compared with an industrial epoxy thermoset prepared from standard diglycidyl ether of Bisphenol A (DGEBA). Results revealed that materials prepared from 3EPOPh were more reactive and showed a tighter network with higher crosslinking density and glass transition temperatures than the prepared from DGEBA. The partial substitution of 3EPOPh by TPTE as epoxy comonomer caused an increase in the molecular mobility of the materials but without worsening the thermal stability. The shape-memory polymers (SMPs) prepared from 3EPOPh showed good mechanical properties as well as an excellent shape-memory performance. They showed almost complete shape-recovery and shape-fixation, fast shape-recovery rates, and recovery stress up to 7 MPa. The results obtained in this study allow us to conclude that the triglycidyl phloroglucinol derivative of eugenol is a safe and environmentally friendly alternative to DGEBA for preparing thermosetting shape-memory polymers.

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

Polymers ◽  
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.

Smart Materials of Cured Epoxy Polymer Modified by 6F-PEEK with Shape Memory Effect

2010 ◽  
Vol 152-153 ◽  
pp. 530-535 ◽  
Author(s):  
Jun Peng Gao ◽  
Chen Qian Zhang ◽  
Xian Cheng He ◽  
Hong Yi Ma ◽  
Xue Feng An ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Smart Materials ◽  
Shape Recovery ◽  
Epoxy Polymer ◽  
Memory Effects ◽  
Retention Rates ◽  
Thermally Induced ◽  
Shape Memory Effects

We demonstrated a method of fabricating thermosetting epoxy polymer with shape memory effect modified Poly (ether ether ketone) (6F-PEEK) based on the formation of a phase-segregated morphology. The peculiarities of shape memory effects of the epoxy resin modified by 6F-PEEK were investigated. DMA result showed two glass transition temperatures in this blended material. The cured epoxy phase showing high Tg of 223oC acted as hard-segment-forming phase the and was responsible for the permanent shape. The 6F-PEEK can be used as switching phase for a thermally induced shape-memory effect. The transition temperature (Ttran) was 150oC, which was between the Tg of cured epoxy and 6F-PEEK. At the special concentrations of 6F-PEEK, the shape memory effect accompanied by a significant increase in volume was observed. The highest shape memory effect was obtained for the blended material with 25.00 wt% of 6F-PEEK. The shape retention rates and the shape recovery rates were 96-99% and 100%, respectively. The times of shape-recovery were all defined in 2 min. The mechanism of shape memory effects and the mechanical properties of the cured resin were discussed.

Study on the Shape Memory Effect of Styrene Copolymer

2010 ◽  
Vol 148-149 ◽  
pp. 1464-1468
Author(s):  
Da Wei Zhang ◽  
Yan Hua Zhang ◽  
Li Hua Zhang ◽  
Shui Hu
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Cross Linking ◽  
Content Increase ◽  
Gel Content ◽  
Reversible Strain ◽  
Styrene Copolymer

This paper is concerned about the synthesis of shape memory styrene copolymer and the investigation of the influence of cross-linking degree on its shape memory effect. The influence of cross-linking degree on shape memory effect of styrene copolymer was investigated through altering the dosage of cross-linking agent. The Tg increased from 65 to 80.7 with the gel content increase from 35% to 80% which is achieved by increasing the dosage of cross-linking agent from 1% to 4%. Moreover, the SMP experienced good SME and the largest reversible strain of the SMP reached as high as 150%. When the copolymer was heated above Tg+30 (different copolymers performed different Tg), the shape recovery speed of the copolymers increased with the gel content increase.

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

MRS Advances ◽  
2016 ◽  
Vol 1 (27) ◽  
pp. 1985-1993 ◽  
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.

Clay montmorillonite-poly(e-caprolactone) electrospun microfiber/epoxy composites with triple shape memory effect

2018 ◽  
Vol 47 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Yubing Dong ◽  
Chen Qian ◽  
Jian Lu ◽  
Yaqin Fu
Keyword(s):  
Electron Microscope ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Memory Polymer ◽  
Thermomechanical Analysis ◽  
Mechanical Analysis ◽  
Content Type ◽  
Fiber Membranes ◽  
Triple Shape Memory

Purpose Epoxy (EP) and polye-caprolactone (PCL) are typical dual-shape memory polymer (DSMP). To get excellent triple-shape memory effect (TSME) polymer composites which are made from EP and PCL. Miscible PCL/EP blend composites have been investigated and compared to the TSMEs with electrospun PCL microfiber membranes/EP composites. Clay montmorillonite (MMT)-modified electrospun PCL microfiber membranes were prepared to improve the shape memory fixities of electrospun PCL microfiber membranes/EP composites. Design/methodology/approach The morphologies of electrospun PCL microfiber membranes and the cross section of PCL/EP composites were studied using a field emission scanning electron microscope (FE-SEM), and the existence of MMT was confirmed by a transmission electron microscope. Thermal mechanical properties were observed by a differential scanning calorimeter (DSC) and a dynamic thermomechanical analysis machine, and the TSMEs were also determined through dynamic mechanical analysis. Findings Results indicate that the TSMEs of electrospun PCL microfiber membranes/EP composites were excellent, whereas the TSMEs of PCL/EP blend composites were poor. The TSMEs of PCL electrospun microfiber membranes/EP composites significantly improved with the addition of the PCL electrospun microfiber modified with moderate MMT. Research limitations/implications Adding a moderate content of MMT into the electrospun PCL fibers, could improve the TSME of the PCL fiber membranes/EP composites. This study was to create a simple and effective method that can be applied to improve the performance of other SMP. Originality/value A novel triple-shape memory composite were made from dual-shape memory EP and electrospun PCL fiber membranes.

Selectively actuated multi-shape memory effect of a polymer multicomposite

2015 ◽  
Vol 3 (48) ◽  
pp. 24532-24539 ◽  
Author(s):  
Wenbing Li ◽  
Yanju Liu ◽  
Jinsong Leng
Keyword(s):  
Magnetic Field ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Alternating Magnetic Field ◽  
Selective Heating ◽  
Radiofrequency Field

The multicomposite styrene-based shape memory polymer can be selectively actuated by applying selective stimuli due to the selective heating properties of Fe3O4(30 kHz alternating magnetic field) and CNT (13.56 MHz radiofrequency field) nanofillers. Therefore, the multicomposite possesses a well-controlled multiple temporary shape recovery capability.

Dual-shape memory effect in radiation crosslinked thermoplastic blends: fabrication, optimization and mechanisms

RSC Advances ◽  
2015 ◽  
Vol 5 (76) ◽  
pp. 61601-61611 ◽  
Author(s):  
Xiang Shi ◽  
Xuemei Wang ◽  
Chao Fu ◽  
Xianghai Ran
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Smart Materials ◽  
Shape Memory Polymers ◽  
Important Class ◽  
Thermoplastic Blends ◽  
Manufacturing Techniques

Recently, as an important class of mechanically active smart materials, thermoplastic dual-shape memory polymers (SMPs) have attracted notable attention and can be fabricated in many different manufacturing techniques.

scholarly journals Switching microobjects from low to high aspect ratios using a shape-memory effect

Soft Matter ◽  
2021 ◽  
Author(s):  
Fabian Friess ◽  
Andreas Lendlein ◽  
Christian Wischke
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Aspect Ratios ◽  
Switching Pattern ◽  
The Common

A switching pattern of polymer micronetwork (MN) particles towards increased rather than the common decreased aspect ratios has been realized. This feature is based on the programming of MN during the shape recovery of a second shape memory polymer.

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