[article]
Titre : |
Building novel functionalities in coatings using supramolecular polymers |
Type de document : |
texte imprimé |
Auteurs : |
Nilesh S. Phalke, Auteur ; Rajesh M. Shah, Auteur |
Année de publication : |
2013 |
Article en page(s) : |
p. 53-62 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Catégories : |
Polymères supramoléculaires Les polymères supramoléculaires sont des longues chaînes linéaires formées par assemblage réversible de composés de faible masse molaire. La réversibilité de l'association confère à ces matériaux des propriétés proches, mais complémentaires de celles des polymères classiques. En effet, dans les conditions d'utilisation, un polymère supra-moléculaire est en équilibre avec son monomère. Par conséquent, en modifiant légèrement les conditions expérimentales (solvant, concentration, température, cisaillement...), il est possible d'allonger ou de raccourcir les chaînes supramoléculaires et donc de changer les propriétés (rhéologiques, mécaniques...) du système. Cette particularité constitue un avantage pour de nombreuses applications potentielles, ainsi qu'une difficulté de caractérisation.
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Tags : |
'Polymères supramoléculaires' 'Liaisons hydrogène' 'Revêtement auto-réparant' Hydrogels 'Composés de coordination' 'Métal-Ligand' 'Host-Guest' 'Plug n play' |
Index. décimale : |
668.9 Polymères |
Résumé : |
Supramolecular polymers are polymeric arrays of monomer units, held together by reversible and highly directional secondary interactions — that is, noncovalent bonds, such as hydrogen bonds. The resulting materials therefore maintain their polymeric properties in solution. The directions and strengths of the interactions are precisely tuned so that the array of molecules behaves as a polymer. The high reversibility of the non-covalent bonds ensures that supramolecular polymers are always formed under conditions of thermodynamic equilibrium, and hence the lengths of the chains are directly related to the strength of the non-covalent bond, the concentration of the monomer and the temperature.
Conventional polymers have excellent properties as materials, but when they melt they become highly viscous due to the result of entanglement of their macromolecules. High temperatures and pressures are typically required to provide a melt of sufficiently low viscosity for processing, and this limits their applications. But supramolecular polymers combine good material properties with low viscosity melts that are easy to handle. Some supramolecular polymers also have remarkable characteristics unique to their class, such as the ability to self-heal the fractures in their structure as they permit a rapid response to a change in environment, resulting in easily controllable strength and selectivity of noncovalent interactions. This enables the tuning of material properties in terms of strength, reversibility and directionality which can be utilized to build novel functionalities in coatings.
In this review, an attempt is made to illustrate the classification, mechanisms and applications of the versatile chemistry of supramolecular polymers. It also focuses on important concepts such as molecular self-assembly, folding, molecular recognition, host-guest chemistry and mechanically-interlocked molecular architectures exhibited by supramolecular chemistry. Practical applications of supramolecular polymer chemistry in coatings technology such as self-healing materials, thermally responsive materials and polymer blends are also discussed. |
Note de contenu : |
- CLASSIFICATION
- SUPRAMOLECULAR POLYMERIZATION MECHANISMS : A. Isodesmic or Multi Stage oOpen Association (MSOA) - B. Ring-chain - C. Cooperative growth or nucleation-elongation - Hydrogen-bonded polymers - Metal-ligand coordination polymers - π-π stacking
- SUPRAMOLECULAR POLYMERIZATION APPROACHES
- APPLICATIONS OF SUPRAMOLECULAR POLYMERS : Self-healing applications in coatings - Oxygen barrier coatings based on supramolecular assembly of melamine - Supramolecular polymeric hydrogels - Phases separation of supramolecular and dynamic block copolymers - Polymer-coated optical sensor offers improved explosives detection - Ink-jet inks - Catalysis and artificial enzymes based on supramolecular scaffolds - Green chemistry
- FUTURE PERSPECTIVES |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=19675 |
in PAINTINDIA > Vol. LXIII, N° 9 (09/2013) . - p. 53-62
[article]
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