Improved shape memory performance of star-shaped POSS-polylactide based polyurethanes (POSS-PLAUs)

RSC Advances ◽  
2015 ◽  
Vol 5 (109) ◽  
pp. 90209-90216 ◽  
Author(s):  
S. Y. Gu ◽  
X. F. Gao
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Memory Performance ◽  
Shape Fixity

Star-shaped POSS-polylactide based polyurethanes with improved shape fixity ratios (above 99%) and shape recovery ratios (around 84%) are presented.

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.

Characristics of Shape Memory Composites Combined with Shape Memory Alloy and Shape Memory Polymer

2013 ◽  
Vol 705 ◽  
pp. 169-172
Author(s):  
Xue Feng ◽  
Li Min Zhao ◽  
Xu Jun Mi
Keyword(s):  
Shape Memory ◽  
Room Temperature ◽  
Shape Recovery ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Young Modulus ◽  
Thermomechanical Properties ◽  
The Matrix ◽  
Shape Memory Composites ◽  
Shape Fixity

In order to develop high functionality of shape memory materials, the shape memory composites combined with TiNi wire and shape memory epoxy were prepared, and the mechanical and thermomechanical properties were studied. The results showed the addition of TiNi wire increased the Young modulus and breaking strength both at room temperature and at elevated temperature. The composites maintained the rates of shape fixity and shape recovery close to 100%. The maximum recovery stress increased with increasing TiNi wire volume fraction, and obtained almost 3 times of the matrix by adding 1vol% TiNi wire.

scholarly journals Determination of Shape Fixity and Shape Recovery Rate of Carbon Nanotube-filled Shape Memory Polymer Nanocomposites

2012 ◽  
Vol 41 ◽  
pp. 1641-1646 ◽  
Author(s):  
Shahrul Azam Abdullah ◽  
Aidah Jumahat ◽  
Nik Rosli Abdullah ◽  
Lars Frormann
Keyword(s):  
Carbon Nanotube ◽  
Shape Memory ◽  
Polymer Nanocomposites ◽  
Recovery Rate ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Shape Fixity

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.

HEAT-TRIGGERED SHAPE MEMORY EFFECT OF PEROXIDE CROSS-LINKED ETHYLENE–METHACRYLIC ACID COPOLYMER/NITRILE–BUTADIENE RUBBER THERMOPLASTIC VULCANIZATES WITH SEA-ISLAND STRUCTURE

2021 ◽  
Author(s):  
Yingtao Sun ◽  
Jiahao Li ◽  
Kerui Liao ◽  
Jing Hua ◽  
Zhaobo Wang
Keyword(s):  
Shape Memory ◽  
Methacrylic Acid ◽  
Shape Recovery ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
Nitrile Butadiene Rubber ◽  
Acid Copolymer ◽  
Thermoplastic Vulcanizates ◽  
Switching Temperature ◽  
Shape Fixity

ABSTRACT Designing shape memory polymers (SMPs) based on thermoplastic vulcanizates (TPVs) is an essential research topic. An efficient SMP is designed with typical sea-island structured ethylene–methacrylic acid copolymer/nitrile–butadiene rubber (EMA/NBR) TPVs in which the heat-control switched phase performed by the EMA phase is related to the shape fixity ability. The results show that the heat-triggered SMPs exhibit surprising shape memory properties (shape fixity >95%, shape recovery >95%, and fast recovery speed <30 s at the switching temperature of 95 °C). Through X-ray diffraction characterization, it is seen that the shape fixity of TPVs is achieved mainly through ethylene crystallization. The switching temperature is largely determined by the melting temperature (98 °C) obtained by differential scanning calorimetery.

108 Shape Fixity, Shape Recovery and Secondary Shape Forming of Polyurethane-Shape Memory Polymer

2006 ◽  
Vol 2006.14 (0) ◽  
pp. 27-28
Author(s):  
Hisaaki TOBUSHI ◽  
Syunichi HAYASHI ◽  
Yoshihiro EJIRI ◽  
Toshimi SAKURAGI
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Shape Fixity

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.

scholarly journals PENGARUH VARIASI JUMLAH BAHAN PENGISI CARBON BLACK TERHADAP SIFAT MEKANIK DAN KARAKTERISTIK KARET ALAM PENGINGAT BENTUK

2020 ◽  
Vol 5 (2) ◽  
pp. 100
Author(s):  
Noor Maryam Setyadewi ◽  
Endang Susiani ◽  
Efa Radnawati
Keyword(s):  
Carbon Black ◽  
Shape Memory ◽  
Shape Recovery ◽  
Spare Part ◽  
Shape Fixity

Indonesia memiliki potensi komoditi karet alam yang besar, dengan modifikasi kimia karet alam dapat di design menjadi material pintar seperti halnya polimer sintetik lainnya. Material pintar yang dikembangkan pada penelitian ini adalah material shape memory atau pengingat bentuk. Material pengingat bentuk yaitu material yang memiliki kemampuan mengingat bentuk permanen, diprogram untuk menjadi bentuk tertentu dibawah lingkungan tertentu (seperti suhu dan pH), dan mampu kembali ke bentuk awalnya. Material pengingat bentuk berpotensi untuk diaplikasikan menjadi sensor, aktuator, alat kesehatan maupun spare part alat transportasi. Karet alam pengingat bentuk dibuat dengan metode swelling cross linked vulkanisat karet alam di dalam larutan asam stearat  dengan suhu 75⁰C - 80⁰C dalam waterbath selama 1 jam. Tujuan dari penelitian ini adalah untuk mempelajari pengaruh variasi jumlah bahan pengisi (carbon black filler) pada 5 sampel (C1, C2, C3, C4, C5) terhadap sifat mekanik dan parameter pengingat bentuk. Hasil pengujian kuat tarik menunjukkan vulkanisat blanko memiliki kecenderungan nilai kuat tarik yang lebih tinggi dibandingkan vulkanisat yang mengalami treatment dengan asam stearat. Nilai shape recovery vulkanisat karet alam pengingat bentuk berkisar 76,9- 95,8% dan nilai shape fixity sebesar 14,8-26,1%.

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