A facile approach to durable, transparent and self-healing coatings with enhanced hardness based on Diels-Alder polymer networks

Abstract

Prolonged durability in outdoor environment and ease of application are highly required features for self-healing coatings. To this end, a novel transparent and self-healing nanocomposite for optical applications, based on Diels-Alder (DA) chemistry is developed in this work. First, a novel, highly soluble, bismaleimide enabled a simple coating fabrication by coupling with furan-functionalized polyacrylates in industrially relevant solvents. The resulting crosslinked coatings exhibited high transparency and complete absence of color, as assessed by UV-vis spectroscopy. Their thermal behavior and the conditions required by the healing process were significantly affected by the degree of furan/maleimide functionality of the system. Secondly, the addition of a small amount of a commercial antioxidant stabilized the optical properties against photo-oxidative weathering, both on clear and titania-pigmented coatings, as determined by colorimetric analysis. Finally, dispersion of silica nanoparticles in the DA-based matrix allowed to enhance the surface hardness of the coatings, while retaining the self-healing ability.

Influencia estadística del NH4OH, número de capas y volumen de gota en el desarrollo de recubrimientos ultra-hidrofóbicos basados en nanopartículas de SiO2

“…There are two approaches to achieve highhydrophobic conditions: (i) increase surface roughness [26][27][28][29], (ii) decrease surface tension [20] [30][31][32][33]. The first approach is related to the idea of reducing, as much as possible, the contact area between liquid and solid, and in turn, being able to create spaces in which air bubbles can be located [20] [31] [34][35][36] that serve as a barrier (protects the drop from morphological irregularities that can undo them).…”

A Structure‐Properties Relationship Study of Self‐Healing Materials Based on Styrene and Furfuryl Methacrylate Cross‐Linked via Diels–Alder Chemistry

“…The use of Diels–Alder [4 + 2] cycloaddition (DA) in the preparation of thermally reversible polymeric materials has been explored extensively in the last three decades. [ 1–4 ] The possibility to reversibly decouple the DA adduct at relatively low temperature (retro‐DA), allows the introduction of reversible cross‐links, thus the preparation of self‐healing and shape‐memory materials, [ 5–7 ] as well as recyclable thermosets, [ 8 ] and reversible fiber reinforced composites, [ 9,10 ] with potentially limitless application, usually in the fields of smart coatings, [ 11–13 ] adhesives, [ 14 ] hydrogels [ 15–17 ] and 3D printing. [ 18 ] The probably most exploited diene/dienophile couple for this purpose is constituted by a furan/maleimide system.…”

“…[ 18 ] The probably most exploited diene/dienophile couple for this purpose is constituted by a furan/maleimide system. These moieties can be incorporated in polymers in several ways, [ 11,15–23 ] as well as on inorganic nanoparticles [ 24 ] and their reaction is reversible in a convenient temperature interval ( Figure ). Our group has contributed to this research with extensive work on polyketone [ 25–29 ] and rubber [ 30,31 ] based systems.…”

Facile Repair of Anti‐Corrosion Polymeric Composite Coatings Based on Light Triggered Self‐Healing

“…Self-healing can be considered as a candidate solution for the maintenance of polymeric coatings for restricted regions. [3][4][5] In the last decades, microcapsules containing repairing agents were mixed with polymeric coatings to achieve autonomous self-healing. [6][7][8] When microcracks pierce microcapsules, repairing agents flow into cracks and heal them via reactions.…”