Thermal and electroactive shape memory behaviors of poly(l-lactide)/thermoplastic polyurethane blend induced by carbon nanotubes

RSC Advances ◽  
2015 ◽  
Vol 5 (123) ◽  
pp. 101455-101465 ◽  
Author(s):  
Li-na Shao ◽  
Jian Dai ◽  
Zhi-xing Zhang ◽  
Jing-hui Yang ◽  
Nan Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Shape Memory ◽  
Thermoplastic Polyurethane ◽  
Good Shape

Selectively located CNTs endowed the PLLA/TPU/CNT blend composites with good shape memory behaviors.

scholarly journals Hybrid Nanocomposites of Cellulose/Carbon-Nanotubes/Polyurethane with Rapidly Water Sensitive Shape Memory Effect and Strain Sensing Performance

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1586 ◽  
Author(s):  
Wu ◽  
Gu ◽  
Hou ◽  
Li ◽  
Ke ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Shape Memory ◽  
Shape Recovery ◽  
Thermoplastic Polyurethane ◽  
Cellulose Nanofibers ◽  
Hybrid Nanocomposites ◽  
Large Strains ◽  
Strain Sensing ◽  
Shape Memory Effects ◽  
Sensing Performance

In this work, a fast water-responsive shape memory hybrid polymer based on thermoplastic polyurethane (TPU) was prepared by crosslinking with hydroxyethyl cotton cellulose nanofibers (CNF-C) and multi-walled carbon nanotubes (CNTs). The effect of CNTs content on the electrical conductivity of TPU/CNF-C/CNTs nanocomposite was investigated for the feasibility of being a strain sensor. In order to know its durability, the mechanical and water-responsive shape memory effects were studied comprehensively. The results indicated good mechanical properties and sensing performance for the TPU matrix fully crosslinked with CNF-C and CNTs. The water-induced shape fixity ratio (Rf) and shape recovery ratio (Rr) were 49.65% and 76.64%, respectively, indicating that the deformed composite was able to recover its original shape under a stimulus. The TPU/CNF-C/CNTs samples under their fixed and recovered shapes were tested to investigate their sensing properties, such as periodicity, frequency, and repeatability of the sensor spline under different loadings. Results indicated that the hybrid composite can sense large strains accurately for more than 103 times and water-induced shape recovery can to some extent maintain the sensing accuracy after material fatigue. With such good properties, we envisage that this kind of composite may play a significant role in developing new generations of water-responsive sensors or actuators.

Palm Oil Polyol/ Polyurethane Shape Memory Nanocomposites

2013 ◽  
Vol 291-294 ◽  
pp. 2666-2669 ◽  
Author(s):  
Syazana Ahmad Zubir ◽  
Ahmad Sahrim ◽  
Ernie Suzana Ali
Keyword(s):  
Shape Memory ◽  
Palm Oil ◽  
Thermoplastic Polyurethane ◽  
Polymerization Process ◽  
Diphenylmethane Diisocyanate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Shape ◽  
Crosslinking Process ◽  
Polyurethane Nanocomposites

A series of nanoclay reinforced thermoplastic polyurethane with shape memory effect have been successfully synthesized via two-step polymerization process. The polyurethanes are composed of polycaprolactonediol, palm oil polyol, 4,4’-diphenylmethane diisocyanate and 1,4-butanediol. Nanoclay was added in order to improve the overall properties of the pristine polyurethane. Besides, the addition of palm oil polyol is believed to enhance the crosslinking process and further improve the properties. X-ray diffraction result showed that there is a decrease in crystallinity of polyurethane nanocomposites as clay is added. Good shape memory and mechanical properties of resulting polyurethane nanocomposites were obtained in this work.

Effect of Carbon Nanotubes on the Shape Memory Performance of Poly(vinylidene fluoride)/Acrylic Blends

2013 ◽  
Vol 30 (2) ◽  
pp. 134
Author(s):  
Hui FU ◽  
Jishan QIU ◽  
Ning CHONG ◽  
Yaqing WANG ◽  
Yuanyuan TIAN ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Shape Memory ◽  
Vinylidene Fluoride ◽  
Memory Performance ◽  
Poly Vinylidene Fluoride

scholarly journals Net-Shape NiTi Shape Memory Alloy by Spark Plasma Sintering Method

2021 ◽  
Vol 11 (4) ◽  
pp. 1802
Author(s):  
Sneha Samal ◽  
Orsolya Molnárová ◽  
Filip Průša ◽  
Jaromír Kopeček ◽  
Luděk Heller ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Spark Plasma Sintering ◽  
Memory Effect ◽  
Niti Alloy ◽  
Niti Shape Memory Alloy ◽  
Good Shape ◽  
Plasma Sintering ◽  
Shape Memory Effects ◽  
Spark Plasma

An analysis of the shape memory effect of a NiTi alloy by using the spark plasma sintering approach has been carried out. Spark plasma sintering of Ti50Ni50 powder (20–63 µm) at a temperature of 900 °C produced specimens showing good shape memory effects. However, the sample showed 2.5% porosity due to a load of 48 MPa. Furthermore, an apparent shape memory effect was recorded and the specimens were characterized by uniformity in chemical composition and shape memory alloys of NiTi showed significant austenite phases with a bending strain recovery of >2.5%.

Physical property of 3D-printed sinusoidal pattern using shape memory TPU filament

2020 ◽  
Vol 90 (21-22) ◽  
pp. 2399-2410 ◽  
Author(s):  
Shahbaj Kabir ◽  
Hyelim Kim ◽  
Sunhee Lee
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Shape Memory ◽  
Fused Deposition Modeling ◽  
Loss Modulus ◽  
Thermoplastic Polyurethane ◽  
Heating Process ◽  
Fused Deposition ◽  
3D Printed ◽  
Sinusoidal Pattern

This study has investigated the physical properties of 3D-printable shape memory thermoplastic polyurethane (SMTPU) filament and its 3D-printed sinusoidal pattern obtained by fused deposition modeling (FDM) technology. To investigate 3D filaments, thermoplastic polyurethane (TPU) and SMTPU filament were examined by conducting infrared spectroscopy, x-ray diffraction (XRD), dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC) and a tensile test. Then, to examine the 3D-printed sinusoidal samples, a sinusoidal pattern was developed and 3D-printed. Those samples went through a three-step heating process: (a) untreated state; (b) 5 min heating at 70°C, cooling for 30 min at room temperature; and (c) a repeat of step 2. The results obtained by the three different heating processes of the 3D-printed sinusoidal samples were examined by XRD, DMTA, DSC and the tensile test to obtain the effect of heating or annealing on the structural and mechanical properties. The results show significant changes in structure, crystallinity and thermal and mechanical properties of SMTPU 3D-printed samples due to the heating steps. XRD showed the increase in crystallinity with heating. In DMTA, storage modulus, loss modulus and the tan σ peak position also changed for various heating steps. The DSC result showed that the Tg for different steps of the SMTPU 3D-printed sample remained almost the same at around 51°C. The tensile property of the TPU 3D-printed sinusoidal sample decreased in terms of both load and elongation with increased heating processes, while for the SMTPU 3D-printed sinusoidal sample, the load decreased but elongation increased about 2.5 times.

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