scholarly journals Bioinspired Energetic Composites with Enhanced Interfacial, Thermal and Mechanical Performance by “grafting to” way

Author(s):  
Cheng-cheng Zeng ◽  
Fei-yan Gong ◽  
Cong-mei Lin ◽  
Guan-song He ◽  
Li-ping Pan ◽  
...  
Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1308 ◽  
Author(s):  
Chengcheng Zeng ◽  
Zhijian Yang ◽  
Jianhu Zhang ◽  
Yubin Li ◽  
Congmei Lin ◽  
...  

The mechanical properties of composites are highly dependent on the interfacial interaction. In the present work, inspired by marine mussel, the adhesion between energetic crystals of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and polymer binders was improved. Three types of linear polymeric agents of glycidyl azide polymer (GAP), polyethylene glycol (PEG), and polytetramethylene ether glycol (PTMEG) were grafted onto TATB particles bridged through polydopamine (PDA) films. SEM images showed that 5% grafting contents could evidently form roughness shells on the surface. With a reinforcement at the interface produced by grafting shells, the mechanical properties of polymer-bonded explosives (PBXs) exhibited outstanding mechanical performance, especially for the PTMEG-grafting sample. Examined by the contact-angle test, the PTMEG-grafting sample possessed a value of polar component similar to that of fluoropolymer, leading to an excellent wettability of the two phases. Additionally, different contents of PTMEG were grafted to reveal that the mechanical properties could be improved even with content as little as 0.5 wt.% PTMEG. These results might highlight a correlation between interfacial interaction and macroscopic properties for mechanically energetic composites, while providing a versatile route of grafting on highly loaded composites.


2019 ◽  
Author(s):  
Peter Peter ◽  
Claudia Creighton ◽  
David Fox ◽  
Pablo Mota Santiago ◽  
Adrian Hawley ◽  
...  

Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.


Author(s):  
Byung-Jae Kim ◽  
Hyeon-Seok Seo ◽  
Won-Ho Lee ◽  
Jong-Hyun Ahn ◽  
Youn-Jea Kim

Diabetes ◽  
1984 ◽  
Vol 33 (12) ◽  
pp. 1138-1143 ◽  
Author(s):  
B. H. Tan ◽  
G. L. Wilson ◽  
S. W. Schaffer

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