Photoinitiated thiol–epoxy addition for the preparation of photoinduced self-healing fatty coatings

Abstract

Herein, we report the use of the photoinitiated thiol–epoxy chemistry for the preparation of a new biosourced self-healing coating.

Stimuli-responsive thiol-epoxy networks with photo-switchable bulk and surface properties

“…Consequently, the curing reaction was monitored by the depletion of the thiol peak at 2580 cm À1 . 17,29 The inuence of the photolatent base content (2-5 wt%) on the curing kinetics was studied by keeping the weight ratio between photolatent base and ITX constant at 1 : 1 (see Fig. 4b).…”

Light-Healable Epoxy Polymer Networks via Anthracene Dimer Scission of Diamine Crosslinker

“…The crosslinker approach, which has been successfully utilized by our group, − allows the formation of a wide range of polymer networks with vastly different self-healing, thermal, and mechanical performance by simple thermal curing of commercially available monomers, in this case epoxies, without the need for complex synthesis often seen when photoresponsive moieties are introduced through monomer synthesis. − The anthracene [4+4] photocycloaddition was utilized as the dynamic chemistry due to the high photoreversibility of the process inside polymer networks, needed to ensure regain of the original polymer network properties after healing. Photocycloaddition has been utilized for light-responsive polymers with great success. − However, the utilization of anthracene is less prevalent, surprisingly so due to its exceptional performance previously demonstrated by works such as Froimowicz et al In contrast to Froimowicz et al, the concentration of anthracene groups in this work is much higher, which as alluded to earlier, will allow a greater change in polymer properties when cleaving the anthracene dimer, allowing for a mechanically robust crosslinked network to transition to a flowable material that ideally can heal scratches.…”

Insight on Mercapto-Coumarins: Synthesis and Reactivity

“…The epoxidized cottonseed oil was used as the main reagent, and it was photocrosslinked in the presence of 0.25 equivalents of 7-mercapto-4-methyl coumarin ( 50 ) as a photodimerizable and healable reactant. The reaction was initiated with 2 wt.% of a photo-based generator porphobilinogen (PBG) ( Scheme 30 ) [ 82 ].…”