Acylhydrazones as Reversible Covalent Crosslinkers for Self-Healing Polymers

2015 ◽  
Vol 25 (22) ◽  
pp. 3295-3301 ◽  
Author(s):  
Natascha Kuhl ◽  
Stefan Bode ◽  
Ranjita K. Bose ◽  
Jürgen Vitz ◽  
Andreas Seifert ◽  
...  
Author(s):  
Natascha Kuhl ◽  
Stefan Bode ◽  
Martin D. Hager ◽  
Ulrich S. Schubert

2021 ◽  
Vol 899 ◽  
pp. 628-637
Author(s):  
Daria V. Zakharova ◽  
Zalina A. Lok’yaeva ◽  
Alexander A. Pavlov ◽  
Alexander V. Polezhaev

We present here a small series of compounds designed to modify the polymer chain of various polyurethanes in order to introduce a structural fragment with the ability of thermally-triggered reversible covalent interactions. Bismaleimides (2a-2e) were synthesized from commercially available aromatic and aliphatic symmetric diamines (1a-1e) and were further introduced into the Diels-Alder reaction with furfuryl alcohol as dienophiles. The Diels-Alder adducts (3a-3e) were obtained as a mixture of endo- and exo-isomer. The presence of symmetrical hydroxyl groups in the structure of the obtained compounds makes them suitable as chain extenders of low molecular weight diisocyanate prepolymers. The presence of a thermally reversible Diels-Alder reaction adduct in the structure of potential chain-extenders opens a possibility to create unique materials with self-healing properties. All compounds obtained were characterized by 1H, 13C NMR, ESI-HRMS, and IR spectroscopy. The thermochemical parameters of the reverse Diels-Alder reaction were established using DSC analysis.


MRS Bulletin ◽  
2008 ◽  
Vol 33 (8) ◽  
pp. 759-765 ◽  
Author(s):  
Kyle A. Williams ◽  
Daniel R. Dreyer ◽  
Christopher W. Bielawski

AbstractOver the past ten years, a broad range of self-healing materials, systems that can detect when they have been damaged and heal themselves either spontaneously or with the aid of a stimulus, has emerged. Although many unique compositions and components are used to create these materials, they all employ basic chemical reactions to facilitate repair processes. Kinetically controlled ring-opening reactions and reversible metal–ligand interactions have proven useful in autonomic self-healing materials, which require no stimulus (other than the formation of damage) for operation. In contrast, nonautonomic self-healing materials, which require some type of externally applied stimulus (such as heat or light) to enable healing functions, have capitalized on chemistries that utilize either reversible covalent bonds or various types of noncovalent interactions. This review describes the underlying chemistries used in state-of-the-art self-healing materials, as well as those currently in development.


2015 ◽  
Vol 6 (42) ◽  
pp. 7368-7372 ◽  
Author(s):  
Borui Zhang ◽  
Zachary A. Digby ◽  
Jacob A. Flum ◽  
Elizabeth M. Foster ◽  
Jessica L. Sparks ◽  
...  

A combination of supramolecular and dynamic covalent linkages were used to create creep limited self-healing materials.


2018 ◽  
Vol 31 (1) ◽  
pp. 51-62 ◽  
Author(s):  
Xiaofei Wang ◽  
Kaifeng Zhao ◽  
Xiaowen Huang ◽  
Xiaoyue Ma ◽  
Yanyan Wei

Over time, automotive coating is bound to be damaged; therefore, it is necessary to give the coating a self-healing ability to make its performance even better. First, furfuryl glycidyl ether (FGE) was synthesized by epichlorohydrin and furfuryl alcohol. Then, furanyl-terminated resin FGE-T5000 was synthesized by polyether amine T5000 and FGE. Finally, 4,4′-diphenylmethane bismaleimide (BDM) was added to FGE-T5000 as a cross-linking agent to form a resin named FGE-T5000-BDM which has Diels–Alder (DA) bonds. The products were characterized by Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance, differential scanning calorimeter, dynamic mechanical analysis, thermogravimetric analysis, optical microscope, tensile tests, and other tests. The results showed that FGE-T5000-BDM demonstrated thermally reversible self-healing property from 50°C to 150°C, and that the best temperature of the DA reaction was 80°C. The gel content of FGE-T5000-BDM was 98%. Also, the glass transition temperature and the initial temperature of the Retro-DA (r-DA) reaction were −58°C and 88°C, respectively. Moreover, the self-healing efficiency of FGE-T5000-BDM was up to 88% after staying at 80°C for 12 h. The innovation shown in this article was that the reversible covalent bonds (DA) were combined with the polyether amines, which produced the characteristics of self-healing. Its unique self-healing properties are useful in some areas, such as automobile coatings and other materials.


2017 ◽  
Vol 8 (7) ◽  
pp. 1263-1271 ◽  
Author(s):  
Ruixue Chang ◽  
Heng An ◽  
Xu Li ◽  
Ruyi Zhou ◽  
Jianglei Qin ◽  
...  

P(NIPAM-co-FPA) contains an aldehyde group and a phenolic ester moiety is synthesized. The aldehyde group can form reversible covalent bonds with hydrazide to endow the polymer gels with self-healing properties. The self-healable polymer gel can be degraded in Na2CO3 solution based on cleavage of phenolic ester bond.


2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Xiaowen Huang ◽  
Xiaofei Wang ◽  
Chuanying Shi ◽  
Yang Liu ◽  
Yanyan Wei

AbstractFirst of all, we will provide a brief background on the self-healing hydrogels we produced which are suitable for the complex environment of nature. In this paper, disulfide bonds and acylhydrazone bonds can be combined in SH-WPU and hydrogen bonds existed in PAMAM. And the hydrogel can achieve self-healing under acid, alkaline, neutral or light environment.Self-healing for 1 h, 24 h and 48 h, the self-healing efficiency is 31.58%, 49.84% and 87.35% respectively. This effect achieved the desired effect and the repair effect is more obvious than previous research results. The hydrogels have potential applications in the field of biomaterials.


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