scholarly journals Diels-Alder-based thermo-reversibly crosslinked polymers: Interplay of crosslinking density, network mobility, kinetics and stereoisomerism

2020 ◽  
Vol 135 ◽  
pp. 109882
Author(s):  
Felipe Orozco ◽  
Jing Li ◽  
Unwana Ezekiel ◽  
Zafarjon Niyazov ◽  
Lauren Floyd ◽  
...  
Keyword(s):  
Crosslinking Density ◽  
Diels Alder ◽  
Network Mobility ◽  
Crosslinked Polymers

Thermodynamics and Stereochemistry of Diels–Alder Polymer Networks: Role of Crosslinker Flexibility and Crosslinking Density

2021 ◽  
Author(s):  
Qing Zhou ◽  
Zhen Sang ◽  
Kartik Kumar Rajagopalan ◽  
Yelena Sliozberg ◽  
Frank Gardea ◽  
...  
Keyword(s):  
Polymer Networks ◽  
Crosslinking Density ◽  
Diels Alder

scholarly journals Multifunctional Biodegradable Polymers with Room Temperature Self-Healing and Rewritable Shape Memory Properties via Diels-Alder Reaction

2018 ◽  
Author(s):  
Shenyang Cai ◽  
Zhe Qiang ◽  
Chao Zeng ◽  
Jie Ren
Keyword(s):  
Shape Memory ◽  
Room Temperature ◽  
Crosslinking Density ◽  
Alder Reaction ◽  
Diels Alder ◽  
Poly Lactic Acid ◽  
Crosslinking Reaction ◽  
Self Healing ◽  
Diels Alder Reaction ◽  
Shape Memory Properties

Here, we present a series of novel block copolymers (BCP) from bio-derived monomers, poly(lactic acid)-block-poly(2,5-furandimethylene succinate) (PLA-b-PFS), in which the furan groups from PFS block can be crosslinked with bis(maleimido) triethylene glycol (M2) through a Diels-Alder reaction. This dynamic crosslinking reaction leads to a network structure for enhancing the mechanical properties compared to their linear BCP analogous. Decreasing the crosslinking density leads to a decrease of glass transition temperature of BCPs and a transition from glassy to rubbery-like behavior at room temperature. This allows a wide tunablity of both elastic moduli and yields of the materials. For the lowest crosslinking density. the material exhibits an over 50% self-healing efficiency at room temperature after five days, attributed to the low Tg (15.2 C) from the introduction of PFS block, allowing sufficient chain mobility for structure re-organization. Moreover, with the appropriate selection of crosslinking density (PLA-b-PFS/M2 (6/1)), it also shows an excellent shape memory property with a high recovery rate of 96.3% and a fixity rate of 97.3%. The permanent shape can be rewriteable due to the reversibility of Diels-Alder reaction. With these advanced functionalities and ease in large-scale fabrication, the PLA-b-PFS/M2 shows great promises for self-healing coatings or films with shape memory properties in a wide variety of applications such as packaging materials

The Diels-Alder Reaction of 2-Ethenyl-1,4-Benzodioxin: A New and Simple Synthesis of Bisaryl Ethers

Synlett ◽  
1989 ◽  
Vol 1989 (01) ◽  
pp. 30-32
Author(s):  
Thomas V. Lee ◽  
Alistair J. Leigh ◽  
Christopher B. Chapleo
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Simple Synthesis ◽  
Diels Alder Reaction

2-NITROBENZOFURAN AS DIENOPHILE IN DIELS-ALDER REACTIONS. A SIMPLE DIBENZOFURANS SYNTHESIS

2009 ◽  
Author(s):  
Pedro Mancini ◽  
Maria Kneeteman ◽  
Claudia Della Rosa
Keyword(s):  
Diels Alder

Trienamines: Their Key Role in Extended Organocatalysis for Diels-Alder Reactions

2013 ◽  
Vol 1 ◽  
Author(s):  
Silvia Reboredo ◽  
Alejandro Parra ◽  
José Alemán
Keyword(s):  
Diels Alder

The intermolecular anthracene-transfer in a regiospecific antipodal C60 difunctionalization

2020 ◽  
Author(s):  
Radu Talmazan ◽  
Klaus R. Liedl ◽  
Bernhard Kräutler ◽  
Maren Podewitz
Keyword(s):  
Noncovalent Interactions ◽  
Interaction Model ◽  
Alder Reaction ◽  
Diels Alder ◽  
Stacking Interactions ◽  
Pi Stacking ◽  
Diels Alder Reaction ◽  
Double Decker ◽  
Anthracene Molecule ◽  
New Strategies

We analyze the mechanism of the topochemically controlled difunctionalization of C60 and anthracene, where an anthracene molecule is transferred from one C60 monoadduct to another one under exclusive formation of equal amounts of C60 and the difficult to make antipodal C60 bisadduct. Our herein disclosed dispersion corrected DFT studies show the anthracene transfer to take place in a synchronous retro Diels-Alder/Diels-Alder reaction: an anthracene molecule dissociates from one fullerene under formation of an intermediate, while already undergoing stabilizing interactions with both neighboring fullerenes, facilitating the reaction kinetically. In the intermediate, a planar anthracene molecule is sandwiched between two neighboring fullerenes and forms equally strong "double-decker" type pi-pi stacking interactions with both of these fullerenes. Analysis with the distorsion interaction model shows that the anthracene unit of the intermediate is almost planar with minimal distorsions. This analysis sheds light on the existence of noncovalent interactions engaging both faces of a planar polyunsaturated ring and two convex fullerene surfaces in an unprecedented 'inverted sandwich' structure. Hence, it sheds light on new strategies to design functional fullerene based materials.<br>

Potassium Arylethynyltrifluoroborate as an Unstrained Dienophile for Ultrafast and On Demand Activation of Bioorthogonal IEDDA Reactions

2019 ◽  
Author(s):  
Zijian Guo ◽  
Bruno Oliveira ◽  
Claudio D. Navo ◽  
Pedro M. S. D. Cal ◽  
Francisco Corzana ◽  
...  
Keyword(s):  
Protein Modification ◽  
Cross Reactivity ◽  
Diels Alder ◽  
Inverse Electron Demand ◽  
On Demand ◽  
Strained Alkenes ◽  
Electron Demand

<p>Strained alkenes and alkynes are the predominant dienophiles used in inverse electron-demand Diels-Alder (IEDDA) reactions, however, their instability, cross-reactivity and accessibility are problematic. Unstrained dienophiles, although physiologically stable and synthetically accessible, react with tetrazines significantly slower relative to strained variants. Here we report the development of potassium arylethynyltrifluoroborates as unstrained dienophiles for ultrafast, chemically triggered IEDDA reactions. By varying the substituents on the tetrazine (e.g. pyridyl- to benzyl-substituents), cycloaddition rates can vary from nearly spontaneous (<i>t</i><sub>1/2</sub>≈ 9 s) to no reaction with the unstrained alkyne-BF3 dienophile. The reported system was applied to protein modification and enabled mutually orthogonal labelling of two distinct proteins.</p>

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