High stretchability, high room temperature self-healing efficiency polyurethane adhesive based on hydrogen bond - can be applied to solid rocket propellant

2021 ◽  
Author(s):  
Jing Tu ◽  
Heng Xu ◽  
Guifeng Xiang ◽  
Ling Chen ◽  
Pingyun Li ◽  
...  

Formation and expansion of cracks in propellant would induce debonding at interface between different constituents, and may even cause explosion of the propellant during launch. One way to prohibit the...

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 773 ◽  
Author(s):  
Yuqing Qian ◽  
Xiaowei An ◽  
Xiaofei Huang ◽  
Xiangqiang Pan ◽  
Jian Zhu ◽  
...  

Dynamic structures containing polymers can behave as thermosets at room temperature while maintaining good mechanical properties, showing good reprocessability, repairability, and recyclability. In this work, alkyl diselenide is effectively used as a dynamic cross-linker for the design of self-healing poly(urea–urethane) elastomers, which show quantitative healing efficiency at room temperature, without the need for any catalysts or external interventions. Due to the combined action of the urea bond and amide bond, the material has better mechanical properties. We also compared the self-healing effect of alkyl diselenide-based polyurethanes and alkyl disulfide-based polyurethanes. The alkyl diselenide has been incorporated into polyurethane networks using a para-substituted amine diphenyl alkyl diselenide. The resulting materials not only exhibit faster self-healing properties than the corresponding disulfide-based materials, but also show the ability to be processed at temperatures as low as 60 °C.


Fuel ◽  
2019 ◽  
Vol 237 ◽  
pp. 405-412 ◽  
Author(s):  
Castillo Griego ◽  
Nadir Yilmaz ◽  
Alpaslan Atmanli

Author(s):  
Liangliang Xia ◽  
Ming Zhou ◽  
Hongjun Tu ◽  
wen Zeng ◽  
xiaoling Yang ◽  
...  

The preparation of room-temperature self-healing polymeric materials with good healing efficiency and high mechanical strength is challenging. Two processes are essential to realise the room-temperature self-healing of materials: (a) a...


2020 ◽  
Vol 117 (21) ◽  
pp. 11299-11305 ◽  
Author(s):  
Hao Wang ◽  
Hanchao Liu ◽  
Zhenxing Cao ◽  
Weihang Li ◽  
Xin Huang ◽  
...  

Glassy polymers are extremely difficult to self-heal below their glass transition temperature (Tg) due to the frozen molecules. Here, we fabricate a series of randomly hyperbranched polymers (RHP) with high density of multiple hydrogen bonds, which showTgup to 49 °C and storage modulus up to 2.7 GPa. We reveal that the hyperbranched structure not only allows the external branch units and terminals of the molecules to have a high degree of mobility in the glassy state, but also leads to the coexistence of “free” and associated complementary moieties of hydrogen bonds. The free complementary moieties can exchange with the associated hydrogen bonds, enabling network reconfiguration in the glassy polymer. As a result, the RHP shows amazing instantaneous self-healing with recovered tensile strength up to 5.5 MPa within 1 min, and the self-healing efficiency increases with contacting time at room temperature without the intervention of external stimuli.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 597 ◽  
Author(s):  
Pei-Chen Zhao ◽  
Wen Li ◽  
Wei Huang ◽  
Cheng-Hui Li

The design of polymers that exhibit both good elasticity and self-healing properties is a highly challenging task. In spite of this, the literature reports highly stretchable self-healing polymers, but most of them exhibit slow elastic recovery behavior, i.e., they can only recover to their original length upon relaxation for a long time after stretching. Herein, a self-healing polymer with a fast elastic recovery property is demonstrated. We used 4-[tris(4-formylphenyl)methyl]benzaldehyde (TFPM) as a tetratopic linker to crosslink a poly(dimethylsiloxane) backbone, and obtained a self-healing polymer with high stretchability and fast elastic recovery upon stretching. The strain at break of the as-prepared polymer is observed at about 1400%. The polymer can immediately recover to its original length after being stretched. The damaged sample can be healed at room temperature with a healing efficiency up to 93% within 1 h. Such a polymer can be used for various applications, such as functioning as substrates or matrixes in soft actuators, electronic skins, biochips, and biosensors with prolonged lifetimes.


2007 ◽  
Vol 179 (5) ◽  
pp. 1003-1027 ◽  
Author(s):  
L. W. Hunter ◽  
Y. Chang ◽  
H. N. Oguz ◽  
J. T. Wilkerson ◽  
A. M. Lennon ◽  
...  

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