Enhanced, hydrophobic, initial-shape programmable shape-memory composites with a bio-based nano-framework via gradient metal-ligand cross-linking

Author(s):  
Xinghuo Wang ◽  
Xueli Yang ◽  
Chuanhui Xu ◽  
Baofeng Lin ◽  
Lihua Fu
Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3479
Author(s):  
Lin Xia ◽  
Jiafeng Meng ◽  
Yuan Ma ◽  
Ping Zhao

We processed a series of shape memory Eucommia rubber (ER) composites with both carbon–carbon and ionic cross-linking networks via a chemical cross-linking method. The influence of the carbon–carbon cross-linking and ion cross-linking degree of ER composites on curing, mechanical, thermal, and shape memory properties were studied by DSC, DMA, and other analytical techniques. Dicumyl peroxide (DCP) and zinc dimethacrylate (ZDMA) played a key role in preparing ER composites with a double cross-linking structure, where DCP initiated polymerization of ZDMA, and grafted ZDMA onto polymer molecular chains and cross-linked rubber molecular chains. Meanwhile, ZDMA combined with rubber macromolecules to build ionic cross-linking bonds in composites under the action of DCP and reinforced the ER composites. The result showed that the coexistence of these two cross-linking networks provide a sufficient restoring force for deformation of shape memory composites. The addition of ZDMA not only improved the mechanical properties of materials, but also significantly enhanced shape memory performance of composites. In particular, Eucommia rubber composites exhibited outstanding mechanical properties and shape memory performance when DCP content was 0.2 phr.


2019 ◽  
Vol 10 (33) ◽  
pp. 4519-4523 ◽  
Author(s):  
Yuichiro Kobayashi ◽  
Tomohiro Hirase ◽  
Yoshinori Takashima ◽  
Akira Harada ◽  
Hiroyasu Yamaguchi

Polymeric materials were prepared by cross-linking them with two independent non-covalent interactions, namely hydrogen bonding and metal–ligand interactions.


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.


2021 ◽  
Vol 419 ◽  
pp. 129437
Author(s):  
Chen Yang ◽  
Rui Zheng ◽  
Muhammad Rizwan Younis ◽  
Jundong Shao ◽  
Lian-Hua Fu ◽  
...  

2021 ◽  
Author(s):  
Lulu Pan ◽  
Jianfeng Ban ◽  
Tiwen Xu ◽  
Ruiquan Liu ◽  
Shaorong Lu

A new type of sisal-based shape memory polyurethane foam (SMPU-PSF) was prepared by chemical cross-linking of hydroxyl groups on sisal cellulose (PSF) with polycaprolactone and MDI, which used PSF as...


2014 ◽  
Vol 88 ◽  
pp. 42-47 ◽  
Author(s):  
Loredana Santo ◽  
Fabrizio Quadrini ◽  
Antonio Accettura ◽  
Walter Villadei

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