Next, it was confirmed that poly-2, made by photochemical ring-opening polymerization, could be thermally depolymerized by heating the solid and converting it back into monomer 2, which could be distilled directly and recovered in 81% yield (Fig. and Fig. ). The ability to chemically recycle poly-2 was an important consideration for making a sorbent that could be separated from bound gold, and then re-made back into the polymer for re-use (see below). More generally, this new photochemical ring-opening polymerization provides ready access to polysulfide polymers, complementing Hasell and Quan's photochemical copolymerizations of elemental sulfur , anionic ring-opening polymerizations pioneered by Penczek , and electrochemical polymerizations developed by us . The use of a continuous flow reactor for this new polymerization technique also provides a pathway to scale-up at the outset, which is important for its intended use in gold mining and electronic waste recycling.