Degradable epoxy resins prepared from diepoxide monomer with dynamic covalent disulfide linkage

Bio‐based epoxy vitrimers: Reprocessibility, controllable shape memory, and degradability

“…When external forces induced mechanical breakage of disulfide bonds, thiol radicals were generated and could rapidly exchange with other disulfide bonds, resulting in self‐healing or reprocessing of crosslinked networks . While the dissociative nature of disulfide bonds in reducing or alkaline conditions permitted the degradation of epoxy resins . In fact, during the preparation of this manuscript, we found that Odriozola et al have reported an attractive epoxy vitrimer based on similar approach as ours .…”

Synthesis of a Bifunctional Base Amplifier Containing a Disulfide Bond and Its Application to Photoreactive Materials

“…The assignment was performed by 1 H-NMR, FT-IR and high resolution MS. PBG 1 Scheme 1. Anionic UV curing materials containing disulfide bonds with PBG 1, BA 2 and bifunctional epoxy resin 3. and epoxy resin 3 that has a disulfide bond were also synthesized according to the literatures [6,8]. Decomposition behavior in polystyrene (PSt) films of 2 (20 wt%) was examined with heating at 160 o C with/without hexamethylenediamine (18 mol%), monitored by FT-IR.…”

“…Epoxy polymers having degradable linkages such as tertiary alkyl ester [2], carbamate [3] and carbonate [4] have been reported, although they required relative high decomposition temperatures above 200 o C. On the other hand, disulfide bond is known to be one of dynamic covalent bonds which would cause disulfide-disulfide exchange reactions under gentle heating [5]. Recently, Otsuka et al proposed epoxy network polymers having disulfide bonds where thiol-disulfide exchange reactions were caused with monofunctional thiols in the presence of bases [6]. However, they applied thermal curing of the resins with aromatic diamine crosslinkers having low nucleophilicity.…”

Transient mechanochromism in epoxy vitrimer composites containing aromatic disulfide crosslinks

“…Recycling of epoxy networks containing 4-AFD crosslinks has also been studied by others. [15][16][17] The exchange mechanism for these aromatic disulfide moieties was theoretically studied, 18 and it was found to undergo through a radical mechanism, rather than metathesis. During the manipulation of the mentioned epoxy resin and composites made thereof, a transient mechanochromic behavior was observed.…”