An excess of elemental sulfur is generated annually from hydrodesulfurization in petroleum refining processes; however, it has a limited number of uses, of which one example is the production of sulfuric acid. Despite this excess, the development of synthetic and processing methods to convert elemental sulfur into useful chemical substances has not been investigated widely. Here we report a facile method (termed ‘inverse vulcanization’) to prepare chemically stable and processable polymeric materials through the direct copolymerization of elemental sulfur with vinylic monomers. This methodology enabled the modification of sulfur into processable copolymer forms with tunable thermomechanical properties, which leads to well-defined sulfur-rich micropatterned films created by imprint lithography. We also demonstrate that these copolymers exhibit comparable electrochemical properties to elemental sulfur and could serve as the active material in Li–S batteries, exhibiting high specific capacity (823 mA h g−1 at 100 cycles) and enhanced capacity retention.
We report on dynamic covalent polymers derived from elemental sulfur that can be used as thermally healable optical polymers for mid-IR thermal imaging applications. By accessing dynamic S–S bonds in these sulfur copolymers, surface scratches and defects of free-standing films of poly(sulfur-random-1,3-diisopropenylbenzene) (poly(S-r-DIB) can be thermally healed, which enables damaged lenses and windows from these materials to be reprocessed to recover their IR imaging performance. Correlation of the mechanical properties of these sulfur copolymers with different curing methods provided insights to reprocess damaged samples of these materials. Mid-IR thermal imaging experiments with windows before and after healing of surface defects demonstrated successful application of these materials to create a new class of “scratch and heal” optical polymers. The use of dynamic covalent polymers as healable materials for IR applications offers a unique advantage over the current state of the art (e.g., germanium or chalcogenide glasses) due to both the dynamic character and useful optical properties of S–S bonds.