scholarly journals Co-Processing of [Fe(NH2trz)3](2ns)2 and UHMWPE into Materials Combining (Spin Crossover and High Mechanical Strength

Sci ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 66
Author(s):  
Manuel Baumgartner ◽  
Raphael Schaller ◽  
Paul Smith ◽  
Irene Weymuth ◽  
Walter Caseri
Keyword(s):  
Mechanical Properties ◽  
Coordination Polymer ◽  
Spin Crossover ◽  
Magnetic Transition ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
High Mechanical Strength ◽  
Flexible Films ◽  
Ultrahigh Molecular Weight ◽  
Crossover Behavior ◽  
Poor Solvent

The coordination polymer [Fe(NH2trz)3](2ns)2 exhibits the rare phenomenon of spin crossover in an attractive temperature range, i.e., somewhat above room temperature. Spin crossover in [Fe(NH2trz)3](2ns)2 is manifest by thermochromism, which is accompanied by a magnetic transition from diamagnetism to paramagnetism. However, [Fe(NH2trz)3](2ns)2 is brittle and difficult to process, which limits its use. In this study, we show that [Fe(NH2trz)3](2ns)2 can be co-processed with ultrahigh molecular weight polyethylene (UHMWPE), which possesses outstanding mechanical properties, particularly when tensile drawn. Therefore, [Fe(NH2trz)3](2ns)2–UHMWPE blends were gel-processed by extrusion, employing a relatively poor solvent, which has recently been shown to offer advantages compared to good solvents. Uniform and flexible films, ribbons and fibers with [Fe(NH2trz)3](2ns)2 fractions as high as 33.3% m/m were obtained that could be readily drawn. Spin crossover in the coordination polymer is retained in these materials, as evident from their thermochromism. The tensile strength and Young’s modulus of the blends exceed those of typical commodity polymers. Thus, the films, ribbons and fibers constitute a special class of multifunctional materials that combine the flexibility and excellent mechanical properties of drawn UHMWPE with the spin crossover behavior of [Fe(NH2trz)3](2ns)2.

scholarly journals Co-Processing of [Fe(NH2trz)3](2ns)2 and UHMWPE into Materials Combining (Spin Crossover and High Mechanical Strength

Sci ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 7
Author(s):  
Manuel Baumgartner ◽  
Raphael Schaller ◽  
Paul Smith ◽  
Irene Weymuth ◽  
Walter Caseri
Keyword(s):  
Mechanical Properties ◽  
Coordination Polymer ◽  
Spin Crossover ◽  
Magnetic Transition ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
High Mechanical Strength ◽  
Flexible Films ◽  
Ultrahigh Molecular Weight ◽  
Crossover Behavior ◽  
Poor Solvent

The coordination polymer [Fe(NH2trz)3](2ns)2 (NH2trz = 4-amino-1,2,4-triazole and 2ns− = counterion 2-naphthalene sulfonate) exhibits the rare phenomenon of spin crossover in an attractive temperature range, i.e., somewhat above room temperature. Spin crossover in [Fe(NH2trz)3](2ns)2 is manifested by thermochromism, which is accompanied by a magnetic transition from diamagnetism to paramagnetism. However, [Fe(NH2trz)3](2ns)2 is brittle and difficult to process, which limits its use. In this study, we show that [Fe(NH2trz)3](2ns)2 can be co-processed with ultrahigh molecular weight polyethylene (UHMWPE), which possesses outstanding mechanical properties, particularly when tensile-drawn. Therefore, [Fe(NH2trz)3](2ns)2–UHMWPE blends were gel-processed by extrusion, employing a relatively poor solvent, which has recently been shown to offer advantages compared to good solvents. Uniform and flexible films, ribbons and fibers with [Fe(NH2trz)3](2ns)2 fractions as high as 33.3% m/m were obtained that could be readily drawn. Spin crossover in the coordination polymer is retained in these materials, as evident from their thermochromism. The tensile strength and Young’s modulus of the blends exceed those of typical commodity polymers. Thus, the films, ribbons and fibers constitute a special class of multifunctional materials that combine the flexibility and excellent mechanical properties of drawn UHMWPE with the spin crossover behavior of [Fe(NH2trz)3](2ns)2.

Effect of Polyethylene Jacket on Swelling Behavior and Mechanical Properties of PVA Hydrogel Nucleus Pulposus Prosthesis

2011 ◽  
Vol 287-290 ◽  
pp. 2042-2045 ◽  
Author(s):  
Jin Gao ◽  
Wei Zhu ◽  
Xian Zhou ◽  
Xiao Gang Li
Keyword(s):  
Mechanical Properties ◽  
Nucleus Pulposus ◽  
Free Water ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Relaxation Property ◽  
Dsc Analysis ◽  
Equilibrium Water Content ◽  
Ultrahigh Molecular Weight ◽  
Pva Hydrogel ◽  
Dimension Ratio

New prosthetic nucleus which consisted of ultrahigh molecular weight polyethylene (UHMWPE) jacket and polyvinyl alcohol (PVA) hydrogel core was prepared and studied. The hydrogels with similar size were encased in polyethylene jacket of different dimension. Studies indicate that with the decrease of jacket dimension, swelling time of prosthetic nucleus increases, the equilibrium water content and volume change ratio decrease. Differential Scanning Caborimetry (DSC) analysis shows that increasing the jacket dimension results in a slight increase of non-freezable bond water and significant increase in free water. The prosthetic nucleus with larger jacket has better stress relaxation property due to the plasticization of non-freezable water. These results suggest that the dimension ratio of jacket to core at 1.19-1.35 is the most suitable for artificial nucleus pulposus

High efficiency fabrication of ultrahigh molecular weight polyethylene submicron filaments/sheets by flash-spinning

2016 ◽  
Vol 36 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Lei Xia ◽  
Peng Xi ◽  
Bo-wen Cheng
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
High Efficiency ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Potential Method ◽  
Forming Process ◽  
Commercial Products ◽  
Ultrahigh Molecular Weight ◽  
Novel Method ◽  
Spinning Speed

Abstract In this study, we propose a novel method for preparing continuous ultrahigh molecular weight polyethylene (UHMWPE) filaments by flash-spinning. The filaments were processed by calendaring to obtain the sheets. The morphology of the filaments and the sheets, the forming process, the optimal fabrication conditions, mechanical properties, spinning speed, and the rate of spinning of the filaments were investigated. The results showed that the filaments were composed of bunches of microfibers and the diameter of the filaments and the microfibers ranged from 0.15 mm to 0.22 mm and 0.2 μm to 5 μm, respectively. For a given concentration of 5 wt% of the UHMWPE, optimal specimens were obtained only when the temperature was in the range 150–210°C and the pressure was in the range 8–20 MPa. The spinning speed and the polymer consumption increased with enhancement in the pressure and the value reached as high as 47.2 m/s and 116.7 g/min, respectively. The properties and the spinning efficiency of the filaments revealed that flash-spinning is a potential method for manufacturing commercial products in various fields of application.

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