scholarly journals Exploiting thermally-reversible covalent bonds for the controlled release of microencapsulated isocyanate crosslinkers

2019 ◽  
Vol 135 ◽  
pp. 23-31 ◽  
Author(s):  
M.E. Budd ◽  
R. Stephens ◽  
A. Afsar ◽  
S. Salimi ◽  
W. Hayes
Keyword(s):  
Controlled Release ◽  
Covalent Bonds ◽  
Reversible Covalent

Self-Healing Polymers Based on Reversible Covalent Bonds

2015 ◽  
pp. 1-58 ◽  
Author(s):  
Natascha Kuhl ◽  
Stefan Bode ◽  
Martin D. Hager ◽  
Ulrich S. Schubert
Keyword(s):  
Self Healing ◽  
Covalent Bonds ◽  
Reversible Covalent

scholarly journals Build-To-Specification Vanillin and Phloroglucinol Derived Biobased Epoxy-Amine Vitrimers

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2645
Author(s):  
Aratz Genua ◽  
Sarah Montes ◽  
Itxaso Azcune ◽  
Alaitz Rekondo ◽  
Samuel Malburet ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Renewable Resources ◽  
Diglycidyl Ether ◽  
Vanillyl Alcohol ◽  
Molecular Architecture ◽  
Covalent Bonds ◽  
Thermoset Resins ◽  
Epoxy Amine ◽  
Reversible Covalent ◽  
Epoxy Matrices

Epoxy resins are widely used in the composite industry due to their dimensional stability, chemical resistance, and thermo-mechanical properties. However, these thermoset resins have important drawbacks. (i) The vast majority of epoxy matrices are based on non-renewable fossil-derived materials, and (ii) the highly cross-linked molecular architecture hinders their reprocessing, repairing, and recycling. In this paper, those two aspects are addressed by combining novel biobased epoxy monomers derived from renewable resources and dynamic crosslinks. Vanillin (lignin) and phloroglucinol (sugar bioconversion) precursors have been used to develop bi- and tri-functional epoxy monomers, diglycidyl ether of vanillyl alcohol (DGEVA) and phloroglucinol triepoxy (PHTE) respectively. Additionally, reversible covalent bonds have been incorporated in the network by using an aromatic disulfide-based diamine hardener. Four epoxy matrices with different ratios of epoxy monomers (DGEVA/PHTE wt%: 100/0, 60/40, 40/60, and 0/100) were developed and fully characterized in terms of thermal and mechanical properties. We demonstrate that their performances are comparable to those of commonly used fossil fuel-based epoxy thermosets with additional advanced reprocessing functionalities.

The Underlying Chemistry of Self-Healing Materials

MRS Bulletin ◽  
2008 ◽  
Vol 33 (8) ◽  
pp. 759-765 ◽  
Author(s):  
Kyle A. Williams ◽  
Daniel R. Dreyer ◽  
Christopher W. Bielawski
Keyword(s):  
Ring Opening ◽  
State Of The Art ◽  
Noncovalent Interactions ◽  
Self Healing ◽  
Covalent Bonds ◽  
The Past ◽  
Ring Opening Reactions ◽  
Ligand Interactions ◽  
Reversible Covalent ◽  
Metal Ligand

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.

Preparation and properties of self-healing polyether amines based on Diels–Alder reversible covalent bonds

2018 ◽  
Vol 31 (1) ◽  
pp. 51-62 ◽  
Author(s):  
Xiaofei Wang ◽  
Kaifeng Zhao ◽  
Xiaowen Huang ◽  
Xiaoyue Ma ◽  
Yanyan Wei
Keyword(s):  
Glycidyl Ether ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Diels Alder ◽  
Proton Nuclear Magnetic Resonance ◽  
Self Healing ◽  
Covalent Bonds ◽  
Reversible Covalent ◽  
Automotive Coating

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.

Using reversible non-covalent and covalent bonds to create assemblies and equilibrating molecular networks that survive 5 molar urea

2019 ◽  
Vol 17 (8) ◽  
pp. 2081-2086 ◽  
Author(s):  
Meagan A. Beatty ◽  
Aidan T. Pye ◽  
Alok Shaurya ◽  
Belim Kim ◽  
Allison J. Selinger ◽  
...  
Keyword(s):  
Self Assembly ◽  
Noncovalent Interactions ◽  
Molecular Networks ◽  
Covalent Bonds ◽  
Reversible Covalent

Molecules that assemble through reversible covalent and noncovalent interactions achieve self-assembly at extreme levels of urea and NaCl.

Dual responsive Pickering emulsions stabilized by constructed core crosslinked polymer nanoparticles via reversible covalent bonds

Soft Matter ◽  
2016 ◽  
Vol 12 (48) ◽  
pp. 9683-9691 ◽  
Author(s):  
Huazhang Guo ◽  
Duanguang Yang ◽  
Mei Yang ◽  
Yong Gao ◽  
Yijiang Liu ◽  
...  
Keyword(s):  
Polymer Nanoparticles ◽  
Pickering Emulsions ◽  
Covalent Bonds ◽  
Crosslinked Polymer ◽  
Dual Responsive ◽  
Reversible Covalent

Investigation of thermo-reversibility of polymer crosslinked by reversible covalent bonds through torque measurement

2013 ◽  
Vol 32 (2) ◽  
pp. 353-358 ◽  
Author(s):  
Weiyi Lv ◽  
Yaseen El-Hebshi ◽  
Bo Li ◽  
Yuzheng Xia ◽  
Riwei Xu ◽  
...  
Keyword(s):  
Torque Measurement ◽  
Covalent Bonds ◽  
Reversible Covalent

Celastrol binds to its target protein via specific noncovalent interactions and reversible covalent bonds

2018 ◽  
Vol 54 (91) ◽  
pp. 12871-12874 ◽  
Author(s):  
Duo Zhang ◽  
Ziwen Chen ◽  
Chaochao Hu ◽  
Siwei Yan ◽  
Zhuoer Li ◽  
...  
Keyword(s):  
Noncovalent Interactions ◽  
Binding Specificity ◽  
Target Protein ◽  
Covalent Bonds ◽  
Reversible Covalent

Celastrol binding to its target protein Nur77 requires specific noncovalent interactions that position celastrol close to a specific cysteine and furthermore confer its binding specificity.

Supramolecular control of electronic properties in aromatic materials

2014 ◽  
Vol 86 (4) ◽  
pp. 471-481 ◽  
Author(s):  
Yan-Fang Chen ◽  
Galina V. Dubacheva ◽  
Kuo-Pi Tseng ◽  
Guillaume Raffy ◽  
André Del Guerzo ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Photophysical Properties ◽  
Supramolecular Interactions ◽  
Conjugated Materials ◽  
Covalent Bonds ◽  
Spontaneous Formation ◽  
Supramolecular Control ◽  
Reversible Covalent

AbstractThe use of supramolecular interactions for controlling the electronic and photophysical properties of organic π-conjugated materials is described. This leads to materials presenting unique properties, such as light-induced switching of polarization (photopolism), or the spontaneous formation of highly luminescent vesicles. In another approach, reversible covalent bonds are used to prepare densely packed fullerene monolayers whose conductivity could be probed using conducting AFM.

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