Shape memory effect of poly(L-lactide)- based polyurethanes with different hard segments

2007 ◽  
Vol 56 (7) ◽  
pp. 840-846 ◽  
Author(s):  
Wenshou Wang ◽  
Peng Ping ◽  
Xuesi Chen ◽  
Xiabin Jing
Author(s):  
Eri Niiyam ◽  
Kanta Tanabe ◽  
Koichiro Uto ◽  
Akihiko Kikuchi ◽  
Mitsuhiro Ebara

This paper reports a rational design of temperature-responsive nanofiber meshes with shape-memory effect. The meshes were fabricated by electrospinning a poly(ε-caprolactone) (PCL)-based polyurethane with different contents of soft and hard segments. The effects of PCL diol/hexamethylene diisocyanate (HDI)/1,4-butanediol (BD) molar ratio in terms of the contents of soft and hard segments on the shape-memory properties were investigated. Although the mechanical property improved with increasing hard segment ratio, optimal shape-memory properties were obtained with a PCL/HDI/BD molar ratio of 1:4:3. At a microscopic level, the original nanofibrous structure was easily deformed into a temporary shape, and recovered its original structure when the sample was reheated. A higher recovery rate (>89%) was achieved even when the mesh was deformed up to 400%. Finally, the nanofiber meshes were used to control the alignment of human mesenchymal stem cells (hMSCs). The hMSCs aligned well along the fiber orientation. The proposed nanofibrous meshes with the shape-memory effect have the potential to serve as in vitro platforms for the investigation of cell functions as well as implantable scaffolds for wound-healing applications.


2019 ◽  
Vol 10 (12) ◽  
pp. 1537-1543 ◽  
Author(s):  
Yongwei Wu ◽  
Zhitao Hu ◽  
Huahua Huang ◽  
Yongming Chen

A desirable triple-shape memory effect showing stable yet easily tunable temporary shapes is achieved using a physically crosslinked network with photo-responsive coumarin-containing poly(ε-caprolactone) as soft segments and poly(l-lactide) as hard segments.


Author(s):  
F. I. Grace

An interest in NiTi alloys with near stoichiometric composition (55 NiTi) has intensified since they were found to exhibit a unique mechanical shape memory effect at the Naval Ordnance Laboratory some twelve years ago (thus refered to as NITINOL alloys). Since then, the microstructural mechanisms associated with the shape memory effect have been investigated and several interesting engineering applications have appeared.The shape memory effect implies that the alloy deformed from an initial shape will spontaneously return to that initial state upon heating. This behavior is reported to be related to a diffusionless shear transformation which takes place between similar but slightly different CsCl type structures.


2003 ◽  
Vol 112 ◽  
pp. 1177-1180 ◽  
Author(s):  
A. Schuster ◽  
H. F. Voggenreiter ◽  
D. C. Dunand ◽  
G. Eggeler

2003 ◽  
Vol 112 ◽  
pp. 765-768 ◽  
Author(s):  
Y. Bellouard ◽  
R. Clavel ◽  
R. Gotthardt ◽  
J. van Humbeeck

Author(s):  
M Bolat ◽  
A Ciocan-Pendefunda ◽  
Z Surlari ◽  
C Bida ◽  
C Balcos ◽  
...  

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