scholarly journals Non Edible Oil-Based Epoxy Resins from Jatropha Oil and Their Shape Memory Behaviors

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2177
Author(s):  
Lu Lu Taung Mai ◽  
Min Min Aung ◽  
Sarah Anis Muhamad Saidi ◽  
Paik San H’ng ◽  
Marwah Rayung ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Temperature Characteristic ◽  
Aliphatic Chain ◽  
Jatropha Oil ◽  
Tetraethylammonium Bromide ◽  
Scanning Calorimetry ◽  
Simple Method ◽  
Good Shape ◽  
Memory Recovery

The use of bio-based polymers in place of conventional polymers gives positives effects in the sense of reduction of environmental impacts and the offsetting of petroleum consumption. As such, in this study, jatropha oil was used to prepare epoxidized jatropha oil (EJO) by the epoxidation method. The EJO was used to prepare a shape memory polymer (SMP) by mixing it with the curing agent 4-methylhexahydrophthalic anhydride (MHPA) and a tetraethylammonium bromide (TEAB) catalyst. The resulting bio-based polymer is slightly transparent and brown in color. It has soft and flexible properties resulting from the aliphatic chain in jatropha oil. The functionality of SMP was analyzed by Fourier transform infrared (FTIR) spectroscopy analysis. The thermal behavior of the SMP was measured by thermogravimetric analysis (TGA), and it showed that the samples were thermally stable up to 150 °C. Moreover, the glass transition temperature characteristic was obtained using differential scanning calorimetry (DSC) analysis. The shape memory recovery behavior was investigated. Overall, EJO/MHPA was prepared by a relatively simple method and showed good shape recovery properties.

scholarly journals Block Copolymers of Poly(ω-Pentadecalactone) in Segmented Polyurethanes: Novel Biodegradable Shape Memory Polyurethanes

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1928
Author(s):  
Katalin Czifrák ◽  
Csilla Lakatos ◽  
Marcell Árpád Kordován ◽  
Lajos Nagy ◽  
Lajos Daróczi ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Mechanical Analysis ◽  
Attenuated Total Reflectance ◽  
Dibutyltin Dilaurate ◽  
Scanning Calorimetry ◽  
Dynamical Mechanical Analysis ◽  
Good Shape ◽  
Segmented Polyurethanes ◽  
Shape Fixity

In this report, the synthesis of poly(ω-pentadecalactone) (PPDL) (co)polymers and their incorporation into polyurethanes (PUs) are reported. Optimal conditions for the ring-opening polymerization (ROP) of ω-pentadecalactone (PDL) using dibutyltin dilaurate catalyst were established. For the synthesis of linear and crosslinked PUs, 50 kDa poly(ε-caprolactone) (PCL) and 1,6-hexamethylenediisocyanate (HDI) were used. The obtained polyurethanes were characterized by Attenuated Total Reflectance Fourier-Transform Infrared spectroscopy (AT-FTIR), differential scanning calorimetry (DSC), and dynamical mechanical analysis (DMA). The DMA of the selected sample showed a rubbery plateau on the storage modulus versus temperature curve predicting shape memory behavior. Indeed, good shape memory performances were obtained with shape fixity (Rf) and shape recovery (Rr) ratios.

Synthesis and Characterization of IPDI Based Shape Memory Polyurethane

2020 ◽  
Vol 1010 ◽  
pp. 142-147
Author(s):  
Nur Athirah Rasli @ Rosli ◽  
Syazana Ahmad Zubir
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Soft Segment ◽  
Shape Memory Polymer ◽  
Palm Kernel ◽  
Hexamethylene Diisocyanate ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Chain Flexibility

Various polyurethane-based shape memory polymer was synthesized using polycaprolactone (PCL) as soft segment and, hexamethylene diisocyanate (HMDI) and isophorone diisocyanate (IPDI) as the hard segments. Palm kernel oil-based polyol was used to replace part of the petroleum-based polyol due to the increasing demand on renewable resources as a result of environmental awareness. The synthesis has been carried out using two step polymerization method. The effects of varying the molar ratio of IPDI/HMDI on material properties such as crystallinity, transition temperature, morphology, shape memory effect and tensile strength were investigated by using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), shape memory test and tensile test. A high IPDI content in SMPU results in better shape memory effect, whereas increasing HMDI content leads to a better chain flexibility. In this work, the incorporation of IPDI contributes to the formation of phase separation which enhance the formation of crystalline soft segment structure while the incorporation of HMDI as isocyanate tend to promote phase mixing which enhance the chain flexibility of the SMPU backbone.

scholarly journals Mono–Material 4D Printing of Digital Shape–Memory Components

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3767
Author(s):  
Dalia Niazy ◽  
Ahmed Elsabbagh ◽  
Mostafa R. Ismail
Keyword(s):  
Energy Consumption ◽  
Built Environment ◽  
Shape Memory ◽  
Shape Change ◽  
Shape Memory Polymer ◽  
Interactive Systems ◽  
Scanning Calorimetry ◽  
Total Recovery ◽  
Temperature Range ◽  
Environment Temperature

Dynamic shading systems in buildings help reduce solar gain. Actuated systems, which depend on renewable energy with reduced mechanical parts, further reduce building energy consumption compared to traditional interactive systems. This paper investigates stimuli-responsive polymer application in architectural products for sustainable energy consumption, complying with sustainable development goals (SDGs). The proposed research method posits that, by varying the infill percentage in a pre-determined manner inside a 3D-printed mono-material component, directionally controlled shape change can be detected due to thermal stimuli application. Thus, motion behavior can be engineered into a material. In this study, PLA+, PETG, TPU and PA 6 printed components are investigated under a thermal cycle test to identify a thermally responsive shape-memory polymer candidate that actuates within the built environment temperature range. A differential scanning calorimetry (DSC) test is carried out on TPU 95A and PA 6 to interpret the material shape response in terms of transitional temperatures. All materials tested show an anisotropic shape-change reaction in a pre-programmed manner, complying with the behavior engineered into the matter. Four-dimensional (4D)-printed PA6 shows shape-shifting behavior and total recovery to initial position within the built environment temperature range.

Toward Material Parameters for Modeling Devices Made From an Epoxy-Based Shape Memory Polymer

2015 ◽  
Author(s):  
Veysel Erel ◽  
Jessica L. Berry ◽  
Arun Srinivasa ◽  
Terry S. Creasy
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Material Behavior ◽  
Elastic Behavior ◽  
Scanning Calorimetry ◽  
Element Analysis ◽  
Simple Tension ◽  
Nonlinear Elastic ◽  
Tension Experiments

Designing devices made from epoxy-based shape memory polymers is difficult because few material behavior parameters are available for these materials in the rubbery/shape changing region. This work examines the rubbery state, greater than 20° C above the glass transition temperature (Tg), as an elastomeric regime suited to characterization with simple tension and planar tension experiments. Differential scanning calorimetry (DSC) results show a 70° C Tg, which agrees with prior research. Simple tension experiments at 100° C exhibited nonlinear elastic behavior, and finite element analysis (FEA) agreed with the constitutive behavior exhibited in the experiments. Planar tension experiments exhibited novel results. The stress/strain response was sigmoidal with a significant plateau in stress followed by rising stress to failure. The typical 10:1 gage width/gage length ratio seemed to over constrain the material. The strain to failure is small, and suggests the material behavior is a hybrid of elastic and hyperelastic behavior.

scholarly journals Obtaining shape memory alloy thin layer using PLD technique

2014 ◽  
Vol 50 (1) ◽  
pp. 69-76 ◽  
Author(s):  
N. Cimpoeşu ◽  
S. Stanciu ◽  
P. Vizureanu ◽  
R. Cimpoeşu ◽  
Cristian Achiţei ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Deposition Process ◽  
Damping Capacity ◽  
Dynamic Mechanical Analyzer ◽  
Scanning Calorimetry ◽  
Material Microstructure ◽  
X Ray ◽  
Good Shape ◽  
Heat Treated

Copper-based shape memory alloy (SMA) was obtained through a classic melting method. The material was analyzed in heat treated and deformed states using scanning electrons microscopy (SEM), dilatometry (DIL), differential scanning calorimetry (DSC), dynamic mechanical analyzer (DMA) and energy dispersive X-ray analyze (EDAX) to establish the material microstructure, memory properties like martensitic transformation domain and rate or damping capacity. The material exhibits a good shape memory effect and high internal friction and it is proposed as target in a pulsed laser deposition (PLD) process for obtaining thin films. The deposition process is described in this paper through presented experimental results on the layer.

Micron Sized Polyurethane Shape-Memory Polymer Beads

2011 ◽  
Vol 239-242 ◽  
pp. 2675-2678
Author(s):  
Yong Zhao ◽  
Wei Min Huang
Keyword(s):  
Shape Memory ◽  
Carbon Fibers ◽  
Joule Heating ◽  
Shape Memory Polymer ◽  
Processing Condition ◽  
Size Control ◽  
Good Shape ◽  
Novel Approach ◽  
The Relationship ◽  
Geometrical Dimensions

We demonstrate a novel approach to produce micron sized shape-memory beads from polyurethane shape-memory polymer (SMP)-dimethylformamide (DMF) solution by joule heating carbon fibers. The relationship between the geometrical dimensions of the resultant SMP beads and processing condition is obtained, which shows the convenience in dimension/size control in fabrication. The fabrication mechanism is revealed and good shape-memory effect is proved.

scholarly journals Analysis of Shape Memory Behavior and Mechanical Properties of Shape Memory Polymer Composites Using Thermal Conductive Fillers

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1107
Author(s):  
Mijeong Kim ◽  
Seongeun Jang ◽  
Sungwoong Choi ◽  
Junghoon Yang ◽  
Jungpil Kim ◽  
...  
Keyword(s):  
Physical Properties ◽  
Shape Memory ◽  
Polymer Composites ◽  
Shape Recovery ◽  
Memory Performance ◽  
Shape Memory Polymer ◽  
Scanning Calorimetry ◽  
Wide Range ◽  
Nanocarbon Materials ◽  
Shape Memory Composite

Shape memory polymers (SMPs) are attracting attention for their use in wearable displays and biomedical materials due to their good biocompatibility and excellent moldability. SMPs also have the advantage of being lightweight with excellent shape recovery due to their low density. However, they have not yet been applied to a wide range of engineering fields because of their inferior physical properties as compared to those of shape memory alloys (SMAs). In this study, we attempt to find optimized shape memory polymer composites. We also investigate the shape memory performance and physical properties according to the filler type and amount of hardener. The shape memory composite was manufactured by adding nanocarbon materials of graphite and non-carbon additives of Cu. The shape-recovery mechanism was compared, according to the type and content of the filler. The shape fixation and recovery properties were analyzed, and the physical properties of the shape recovery composite were obtained through mechanical strength, thermal conductivity and differential scanning calorimetry analysis.

Thermomechanical Characterization of a Series of Crosslinked Poly[ethylene-co-(vinyl acetate)] (PEVA) Copolymers

2015 ◽  
Vol 1718 ◽  
pp. 123-130 ◽  
Author(s):  
Matthias Heuchel ◽  
Laith Al-Qaisi ◽  
Karl Kratz ◽  
Ulrich Nöchel ◽  
Marc Behl ◽  
...  
Keyword(s):  
Shape Memory ◽  
Vinyl Acetate ◽  
Mechanical Stability ◽  
Shape Memory Polymer ◽  
Thermomechanical Properties ◽  
Scanning Calorimetry ◽  
Temperature Range ◽  
Shape Memory Effects ◽  
Cross Links ◽  
Poly Ethylene

ABSTRACTCrosslinked poly[ethylene-co-(vinyl acetate)] (cPEVA) has been recently introduced as a polymer material, which can be functionalized with various shape-memory effects by solely altering the thermomechanical treatment called programming.In this study two series of cPEVAs with different vinyl acetate contents of 18 wt% (cPEVA18) and 28 wt% (cPEVA28) comprising different crosslink densities were investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) in the temperature range of -130 °C to 120 °C. DMTA tests were performed in torsion mode, because such movements are highly relevant in the context of complex shape changes in shape-memory polymer based devices. Finally, the obtained DMTA results were compared with DMTA conducted in tension mode. Swelling experiments revealed a gel content in the range from 81% to 90% for cPEVA18 samples while for cPEVA28s a complete conversion was observed. The degree of swelling was found to decrease substantially with increasing crosslink density for both cPEVA series.The influence of VA content and extent of crosslinking on the appearance of the respective melting (Tm) and glass transition (Tg) as well as the thermomechanical properties of cPEVA systems could be demonstrated by discussing both DSC and DMTA results. The temperature range of mechanical stability correlates with the VA content and is determined by decreasing Tm values. The cross links do barely alter the stiffness of a PEVA up to the Tm rang, but lead to constant mechanical rigidity in the rubbery range above Tm.

Cross-linked ethylene-vinyl acetate – poly(urethane) temperature-memory composite actuator

2020 ◽  
Vol 54 (28) ◽  
pp. 4441-4455
Author(s):  
JE Rodriguez ◽  
DH Giraldo ◽  
JC Restrepo ◽  
HA Colorado
Keyword(s):  
Shape Memory ◽  
Vinyl Acetate ◽  
Shape Memory Polymer ◽  
Ethylene Vinyl Acetate ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Polymeric Systems ◽  
Responsive Polymers ◽  
The Matrix ◽  
The Relationship

Semicrystalline polymeric systems are a type of Shape Memory Polymer (SMP), which are more straightforward to synthesize in comparison with other class of stimulus-responsive polymers. On these systems, the shape memory is triggered by temperature and partially driven by crystallization-induced elongation, heating-induced contraction, and elastic entropy. However, a stable temporary and permanent shape through cycling is not easy to achieve. For that reason, a laminar composite made based in the encapsulation of ethylene vinyl acetate (EVA) inside a PU matrix was developed, with the aim of obtaining an actuator with a preferred deformation direction and stable change of shape. In this study, chemically cross-linked ethylene vinyl acetate copolymer (cEVA) as SMP was synthesized and functionalized as a reinforcing strip. A temperature-memory actuator composite was manufactured by the encapsulation of a shape memory programmed strip in an elastomer matrix. The shape memory properties and thermocycling assessment were evaluated using differential scanning calorimetry and dynamic mechanical analysis. Results show the ability of the actuator to bend and unbend, following multiple consecutive heating-cooling cycles. The relationship between the strip, the matrix, and the interface is critical in the bending and shape memory maintenance.

scholarly journals Recording, Storage, and Reproduction of Information on Polyvinyl Chloride Films Using Shape Memory Effects

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1802
Author(s):  
Alexander P. Kondratov ◽  
Egor P. Cherkasov ◽  
Vladislav Paley ◽  
Alex A. Volinsky
Keyword(s):  
Shape Memory ◽  
Polyvinyl Chloride ◽  
High Speed ◽  
Screen Printing ◽  
Shape Memory Polymer ◽  
Organic Liquids ◽  
Processing Temperature ◽  
Hidden Information ◽  
Scanning Calorimetry ◽  
Small Surface

Partial dissolution and plasticization are used for recording, storing, and reproducing information with modified industrial screen-printing equipment and aqueous solutions of colorless organic liquids on small surface area shape memory polymer films. To justify the choice of “ink” and evaluate the effectiveness of using organic liquids as high-speed polymer solvents, the new method for recording hidden information uses the calculation of the solubility parameter, differential scanning calorimetry, and the method of one-sided swelling of films under isometric conditions. Using the example of tactile marking of shrink labels made of polyvinyl chloride, the optimal conditions for recording hidden information on a film are established in terms of the concentration of an aqueous solution of tetrahydrofuran, the contact time, and the processing temperature of the polymer using screen printing equipment.

Sign in / Sign up

Export Citation Format

Share Document