Scheme 1.

Light initiated radical network degradation. a Thiyl radicals react with an allyl sulfide to form a radical intermediate that subsequently undergoes beta scission, resulting in the fragmentation of crosslinks and the regeneration of a thiyl radical and allyl sulfide. b A soluble thiol species (red) exchanges with the allyl sulfide, resulting in a cleaved crosslink and the generation of a network tethered thiyl radical. The released network thiyl radical undergoes chain transfer to a soluble thiol species, which can initiate further exchange reactions, amplifying the degradation process.