Shape-Memory Polymers with Adjustable High Glass Transition Temperatures

2015 ◽  
Vol 48 (11) ◽  
pp. 3582-3589 ◽  
Author(s):  
Xinli Xiao ◽  
Deyan Kong ◽  
Xueying Qiu ◽  
Wenbo Zhang ◽  
Fenghua Zhang ◽  
...  
Keyword(s):  
Glass Transition ◽  
Shape Memory ◽  
Shape Memory Polymers ◽  
Transition Temperatures ◽  
Glass Transition Temperatures

Multiple shape memory polymers for self-deployable device

RSC Advances ◽  
2016 ◽  
Vol 6 (56) ◽  
pp. 50581-50586 ◽  
Author(s):  
Shuyun Zhuo ◽  
Gongzheng Zhang ◽  
Xianqi Feng ◽  
Haoyang Jiang ◽  
Jinli Shi ◽  
...  
Keyword(s):  
Glass Transition ◽  
Shape Memory ◽  
Shape Memory Polymers ◽  
Transition Temperatures ◽  
Glass Transition Temperatures

Three-segments MH copolymers with well-separated glass transition temperatures can subsequently change their shapes in a pre-defined way.

scholarly journals Epoxy Resin Composite Bilayers with Triple-Shape Memory Effect

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xixi Li ◽  
Yaofeng Zhu ◽  
Yubing Dong ◽  
Meng Liu ◽  
Qingqing Ni ◽  
...  
Keyword(s):  
Glass Transition ◽  
Electron Microscope ◽  
Shape Memory ◽  
Memory Effects ◽  
Epoxy Composites ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Shape Memory Effects ◽  
Triple Shape Memory ◽  
Nanosilica Particles

Triple-shape memory epoxy composites with bilayer structures of well-separated glass transition temperatures have been successfully prepared. The different glass transition temperatures of the epoxy composites were obtained by physically incorporating various amounts of nanosilica particles, which were introduced into the epoxy by utilizing polyethylene glycol. A scanning electron microscope and a transmission electron microscope were used to analyze the dispersibility of the nanosilica particles. The effects of nanosilica particles on the mechanical properties as well as on the dual-shape memory effects (DSME) and triple-shape memory effects (TSME) of the nanocomposites were studied. The nanosilica particles were homogenously dispersed in the matrix and well incorporated into the epoxy matrix. The resulting nanocomposites exhibited excellent TSME, and their shape fixity properties were significantly improved by nanosilica particles.

Study on Shape Recovery Behaviors of Epoxy-Based Shape Memory Polymer

2011 ◽  
Vol 179-180 ◽  
pp. 325-328 ◽  
Author(s):  
Bo Zhou ◽  
Xue Lian Wu ◽  
Yan Ju Liu ◽  
Jin Song Leng
Keyword(s):  
Glass Transition ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Numerical Calculations ◽  
Glass Transition Temperatures ◽  
Recovery Experiment

The glass transition temperatures of epoxy-based shape memory polymers (SMPs), which contain a flexibilizer at various contents of 0%, 5%, 10% and 15% respectively, are determined through DMA tests. The shape memory effect of such materials is investigated through shape recovery experiments. Experimental results show that the content of flexibilizer has much influence on the shape memory effect of epoxy-based SMP. A shape recovery equation is developed based on the results of shape recovery experiment. Numerical calculations show that the developed shape recovery equation well predicts the shape recovery behaviors of epoxy-based SMP.

Free Recovery Effects of Shape-Memory Polymers for Cardiovascular Stents

2005 ◽  
Vol 898 ◽  
Author(s):  
Christopher Michael Yakacki ◽  
Robin Shandas ◽  
Craig Lanning ◽  
Ken Gall
Keyword(s):  
Glass Transition ◽  
Shape Memory ◽  
Polymer Networks ◽  
Transition Temperatures ◽  
Poly Ethylene Glycol ◽  
Glass Transition Temperatures ◽  
Cardiovascular Stents ◽  
Geometrical Features ◽  
Poly Ethylene ◽  
Free Strain

AbstractThe shape-memory effect was examined in polymer stents intended for cardiovascular applications. Four polymer networks were synthesized from poly(ethylene glycol) dimethacrylate and tert-butyl acrylate with 10 wt% and 20 wt% crosslinker, and with glass transition temperatures (Tg) of 52°C and 55°C. Solid and 50% porous stents were manufactured and tested for free strain recoverability at temperatures at or just above 37°C. Stents with lower glass transition temperatures and a higher degree of crosslinking recovered faster than their counterparts. Lower deformation (packaging) temperatures and higher recovery temperatures induce more rapid recovery. The presence of geometrical features, such as pores, initiated recovery sooner, but had negligible influence on overall recovery.

Novel Bismaleimide-Based Shape Memory Polymers: Comparison to Commercial Shape Memory Polymers

2011 ◽  
Author(s):  
Amber J. W. McClung ◽  
Joseph A. Shumaker ◽  
Jeffery W. Baur
Keyword(s):  
Shape Memory ◽  
Memory Performance ◽  
Shape Memory Polymers ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Transition Temperatures ◽  
Thermal And Mechanical Properties ◽  
Glass Transition Temperatures ◽  
Tan Δ ◽  
Heat Loads

A series of novel shape memory polymers, synthesized from 4-4-bismaleimidodiphenyl-methane, an extended chain aliphatic diamine, and a bis-isocyanate, have been created and characterized with the aim of providing a family of robust high temperature shape memory polymers with tailorable transition temperatures for use in reconfigurable aerospace structures. In the present study, three of the polymers are chosen for more detailed study of their thermomechanical properties. These materials are compared to commercial resins Veriflex® and Veriflex-E® which are styrene- and epoxy-based proprietary formulations, respectively. The thermal and mechanical properties are determined utilizing thermogravimetric analysis and dynamic mechanical analysis. The temperatures at which 2% weight loss is observed in dry air ranges from 272 to 305 °C for the synthesized polymers, and occurs at 242 and 317 °C for the commercial Veriflex® and Veriflex-E® respectively. The glass transition temperatures, as measured by the peak in the tan(δ) curve, for the synthesized polymers range from 110 to 144 °C which is a higher than the Veriflex® and Veriflex-E® achieve at 84.3 and 100 °C respectively. With operation temperatures of subsonic structural aircraft components often reaching 121 °C (250 °F), the transition temperatures of the bismaleimide-based shape memory polymers are clearly desirable to ensure that shape memory polymers used in aircraft structures will not be prematurely triggered by the existing heat loads. In addition, the shape memory performance of the bismaleimide-based shape memory polymers compares well with the Veriflex® and Veriflex-E® resins.

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