scholarly journals Enhancement in Mechanical and Shape Memory Properties for Liquid Crystalline Polyurethane Strengthened by Graphene Oxide

Polymers ◽  
2016 ◽  
Vol 8 (7) ◽  
pp. 236 ◽  
Author(s):  
Yueting Li ◽  
Huiqin Lian ◽  
Yanou Hu ◽  
Wei Chang ◽  
Xiuguo Cui ◽  
...  
Author(s):  
Jianfeng Ban ◽  
Linjiang Zhu ◽  
Shaojun Chen ◽  
Yiping Wang

To better understand the shape memory materials and self-healing materials, a new series of liquid-crystalline shape memory polyurethane (LC-SMPU) composites, named SMPU-OOBAm, were successfully prepared by incorporating 4-octyldecyloxybenzoic acid (OOBA) into the PEG-based SMPU. The effect of OOBA on the structure, morphology and properties has been carefully investigated. The results demonstrate that SMPU-OOBAm have liquid crystalline properties, triple-shape memory properties and self-healing properties. The incorporated OOBA promotes the crystallizability of both soft and hard segments of SMPU, and the crystallization rate of the hard segment of SMPU decreases when the OOBA-content increases. Additionally, the SMPU-OOBAm forms a two-phase separated structure (SMPU phase and OOBA phase), and it shows two-step modulus changes upon heating. Therefore, the SMPU-OOBAm shows triple-shape memory behavior, and the shape recovery ratio decreases with an increase in the OOBA content. Finally, SMPU-OOBAm shows self-healing properties. The new mechanism can be ascribed to the heating-induced “bleeding” of OOBA in the liquid crystalline state and the subsequent re-crystallization upon cooling. This successful combination of liquid crystalline properties, triple-shape memory properties and self-healing properties make the SMPU-OOBAm composites with many promise applications in smart optical devices, smart electronic devices and smart sensors.


2018 ◽  
Vol 159 ◽  
pp. 251-258 ◽  
Author(s):  
Angela Marotta ◽  
Giuseppe Cesare Lama ◽  
Veronica Ambrogi ◽  
Pierfrancesco Cerruti ◽  
Marta Giamberini ◽  
...  

2010 ◽  
Vol 428-429 ◽  
pp. 391-393 ◽  
Author(s):  
Li Yan Liang ◽  
De Wen Zhou ◽  
Man Geng Lu

A series of shape memorized liquid crystalline epoxides with different length of lateral substituents were prepared with several kinds of hardener. The dynamic mechanical analysis and the sharp memory properties of the resulted LC epoxy resins were studied by POM, WAXD, DSC and DMA. The results showed that the modulus in the rubbery region (ER) of the LC epoxides decreases as the length of lateral alkyl groups increases. And the shape memory properties were strongly impacted not only by the length of lateral substituents, but also by the kinds of hardener. The recovering speeds of the shape-memory liquid crystalline epoxides decrease as the increasing length of lateral alkyl groups. And recovering speeds of LC epoxides cured with aromatic amine (DDM) are faster than that of LC epoxides cured with anhydride (THHPA). The local ordered structures and the lateral substituents played an important role in shape memory effects.


2017 ◽  
Vol 321 ◽  
pp. 502-509 ◽  
Author(s):  
Shunli Liu ◽  
Fang Yao ◽  
Olayinka Oderinde ◽  
Kewen Li ◽  
Hongjiao Wang ◽  
...  

2018 ◽  
Vol 9 (5) ◽  
pp. 576-583 ◽  
Author(s):  
Shaojun Chen ◽  
Jianfeng Ban ◽  
Luona Mu ◽  
Haitao Zhuo

Novel liquid crystalline shape memory polymer composites with interesting staging-responsive shape memory properties were successfully prepared. The liquid crystalline shape memory polymer composites maintain the intrinsic reversible liquid crystalline properties of Azo11.


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