Synthesis of thermoplastic polyurethane and its physical and shape memory properties

2006 ◽  
Vol 102 (1) ◽  
pp. 607-615 ◽  
Author(s):  
Huei-Hsiung Wang ◽  
Uen-En Yuen
Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1234 ◽  
Author(s):  
Hongjie Bi ◽  
Min Xu ◽  
Gaoyuan Ye ◽  
Rui Guo ◽  
Liping Cai ◽  
...  

In this study, a series of heat-induced shape memory composites was prepared by the hot-melt extrusion and three-dimensional (3D) printing of thermoplastic polyurethane (TPU) using wood flour (WF) with different contents of EPDM-g-MAH. The mechanical properties, microtopography, thermal property analysis, and heat-induced shape memory properties of the composites were examined. The results showed that, when the EPDM-g-MAH content was 4%, the tensile elongation and tensile strength of the composites reached the maximum value. The scanning electron microscopy and dynamic mechanical analysis results revealed a good interface bonding between TPU and WF when the EPDM-g-MAH content was 4%. The thermogravimetric analysis indicated that the thermal stability of TPU/WF composites was enhanced by the addition of 4% EPDM-g-MAH. Heat-induced shape memory test results showed that the shape memory performance of composites with 4% EPDM-g-MAH was better than that of unmodified-composites. The composites’ shape recovery performance at a temperature of 60 °C was higher than that of the composites at ambient temperature. It was also found that, when the filling angle of the specimen was 45°, the recovery angle of the composites was larger.


2018 ◽  
Vol 47 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Changchun Wang ◽  
Bo Kou ◽  
Zusheng Hang ◽  
Xuejuan Zhao ◽  
Tianxuan Lu ◽  
...  

Purpose This study aims to present that the chemo-responsive shape recovery of thermoplastic polyurethane (TPU) is tunable by solvents with different solubility parameters, and it is generic for chemo-responsive shape-memory polymer and its composites. Design/methodology/approach Two kinds of commercial TPU samples with different thicknesses were prepared by panel vulcanizer and injection molding (an industrial manner) to investigate their chemo-responsive shape memory properties in acetic ether and acetone. Findings Results showed that all of TPU films with different thicknesses can fully recover their original shapes weather they recover in acetic ether or acetone. But the recovery time of TPU films in acetone is greatly reduced, especially for the twisting samples. The residual strains of recovery TPU samples after extension reduce obviously. Research limitations/implications The great decrement of recovery time is related to two factors. One is due to the bigger solubility parameter of acetone with higher dipole moment compared with those of acetic ether, and the other is the remained internal stress of TPU films after preparation. The internal stress is identified to have an effect on the shape-memory properties by comparing the recovery process of samples with/without annealing. The reduced residual strains of recovery TPU samples after extension is due to the increasing mobility of polymer segments after molecules of acetic ether penetrates into the polymeric chains. Originality/value This is a universal strategy to control the recovery process of shape-memory materials or composites. The underlying mechanism is generic and should be applicable to chemo-responsive shape-memory polymers or their composites.


2021 ◽  
pp. 51000
Author(s):  
Fathin Hani Azizul Rahim ◽  
Abdul Aziz Saleh ◽  
Raa Khimi Shuib ◽  
Ku Marsilla Ku Ishak ◽  
Zuratul Ain Abdul Hamid ◽  
...  

2020 ◽  
Vol 90 (21-22) ◽  
pp. 2399-2410 ◽  
Author(s):  
Shahbaj Kabir ◽  
Hyelim Kim ◽  
Sunhee Lee

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.


2013 ◽  
Vol 80 ◽  
pp. 92-97 ◽  
Author(s):  
Semra Ergen ◽  
Orhan Uzun ◽  
Fikret Yilmaz ◽  
M. Fatih Kiliçaslan

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