Thermoreversible Folding as a Route to the Unique Shape-Memory Character in Ductile Polymer Networks

2018 ◽  
Vol 10 (26) ◽  
pp. 22739-22745 ◽  
Author(s):  
Matthew K. McBride ◽  
Maciej Podgorski ◽  
Shunsuke Chatani ◽  
Brady T. Worrell ◽  
Christopher N. Bowman
Keyword(s):  
Shape Memory ◽  
Polymer Networks ◽  
Ductile Polymer ◽  
Unique Shape

scholarly journals Thermally-Induced Shape-Memory Behavior of Degradable Gelatin-Based Networks

2021 ◽  
Vol 22 (11) ◽  
pp. 5892
Author(s):  
Axel T. Neffe ◽  
Candy Löwenberg ◽  
Konstanze K. Julich-Gruner ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Polymer Networks ◽  
Water Soluble ◽  
Compression Tests ◽  
Thermally Induced ◽  
Thermomechanical Process ◽  
Triple Helices

Shape-memory hydrogels (SMH) are multifunctional, actively-moving polymers of interest in biomedicine. In loosely crosslinked polymer networks, gelatin chains may form triple helices, which can act as temporary net points in SMH, depending on the presence of salts. Here, we show programming and initiation of the shape-memory effect of such networks based on a thermomechanical process compatible with the physiological environment. The SMH were synthesized by reaction of glycidylmethacrylated gelatin with oligo(ethylene glycol) (OEG) α,ω-dithiols of varying crosslinker length and amount. Triple helicalization of gelatin chains is shown directly by wide-angle X-ray scattering and indirectly via the mechanical behavior at different temperatures. The ability to form triple helices increased with the molar mass of the crosslinker. Hydrogels had storage moduli of 0.27–23 kPa and Young’s moduli of 215–360 kPa at 4 °C. The hydrogels were hydrolytically degradable, with full degradation to water-soluble products within one week at 37 °C and pH = 7.4. A thermally-induced shape-memory effect is demonstrated in bending as well as in compression tests, in which shape recovery with excellent shape-recovery rates Rr close to 100% were observed. In the future, the material presented here could be applied, e.g., as self-anchoring devices mechanically resembling the extracellular matrix.

Unique Shape Memory Elastomer Associated with Reversible Sacrificial Hydrogen Bonds: Tough and Flexible When below Its Tg

2018 ◽  
Vol 20 (7) ◽  
pp. 1800051 ◽  
Author(s):  
Tengfei Lin ◽  
Siyuan Li ◽  
Jinhuang Ke ◽  
Yuying Zheng ◽  
Yan Yu
Keyword(s):  
Hydrogen Bonds ◽  
Shape Memory ◽  
Unique Shape

Photo-Cross-Linkable Coumarin-Based Poly(ε-caprolactone) for Light-Controlled Design and Reconfiguration of Shape-Memory Polymer Networks

2018 ◽  
Vol 52 (2) ◽  
pp. 444-456 ◽  
Author(s):  
Thomas Defize ◽  
Jean-Michel Thomassin ◽  
Heidi Ottevaere ◽  
Cédric Malherbe ◽  
Gauthier Eppe ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Polymer Networks

Ability to Control the Glass Transition Temperature of Amorphous Shape-Memory Polyesterurethane Networks by Varying Prepolymers in Molecular Mass as well as in Type and Content of Incorporated Comonomers

2009 ◽  
Vol 1190 ◽  
Author(s):  
Joerg Zotzmann ◽  
Steffen Kelch ◽  
Armin Alteheld ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Glass Transition ◽  
Minimally Invasive Surgery ◽  
Shape Memory ◽  
Molecular Mass ◽  
Amorphous Polymer ◽  
Polymer Networks ◽  
Precise Control ◽  
Low Weight ◽  
Switching Temperature ◽  
Selection Of

AbstractThe need of intelligent implant materials for applications in the area of minimally invasive surgery leads to tremendous attention for polymers which combine degradability and shape-memory capability. Application of heat, and thereby exceeding a certain switching temperature Tsw, causes the device to changes its shape. The precise control of Tsw is particularly challenging. It was investigated in how far Tg, that can be used as Tsw, of amorphous polymer networks from star-shaped polyester macrotetrols crosslinked with a low-weight linker can be controlled systematically by incorporation of different comonomers into poly(rac-lactide) prepolymers. The molecular mass of the prepolymers as well as type and content of the comonomers was varied. The Tg could be adjusted by selection of comonomer type and ratio without affecting the advantageous elastic properties of the polymer networks.

Shape memory polymer networks from styrene copolymer

2007 ◽  
Author(s):  
Dawei Zhang ◽  
Xiaoguang Wang ◽  
Wuyi Zhang ◽  
Yanju Liu ◽  
Jinsong Leng
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Polymer Networks ◽  
Styrene Copolymer

Relation between temperature memory effect and multiple-shape memory behaviors based on polymer networks

RSC Advances ◽  
2014 ◽  
Vol 4 (39) ◽  
pp. 20364 ◽  
Author(s):  
Yaru Wang ◽  
Jing Li ◽  
Xingjian Li ◽  
Yi Pan ◽  
Zhaohui Zheng ◽  
...  
Keyword(s):  
Shape Memory ◽  
Memory Effect ◽  
Polymer Networks ◽  
Temperature Memory Effect
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