Catalytic inverse vulcanization

Abstract

The discovery of inverse vulcanization has allowed stable polymers to be made from elemental sulfur, an unwanted by-product of the petrochemicals industry. However, further development of both the chemistry and applications is handicapped by the restricted choice of cross-linkers and the elevated temperatures required for polymerisation. Here we report the catalysis of inverse vulcanization reactions. This catalytic method is effective for a wide range of crosslinkers reduces the required reaction temperature and reaction time, prevents harmful H2S production, increases yield, improves properties, and allows crosslinkers that would be otherwise unreactive to be used. Thus, inverse vulcanization becomes more widely applicable, efficient, eco-friendly and productive than the previous routes, not only broadening the fundamental chemistry itself, but also opening the door for the industrialization and broad application of these fascinating materials.

Combining agriculture and energy industry waste products to yield recyclable, thermally healable copolymers of elemental sulfur and oleic acid

“…The aliphatic chain provided by the stearic acid interacts strongly with the rubber, so that the rubber and sulfur components are held in close proximity on a molecular scale to facilitate interfacial interaction. Hasell recently reported that certain transition metal salts likewise facilitate the compatibility of previously unreactive olefins for successful inverse vulcanization …”

“…Some high‐temperature reactions of organics with elemental sulfur are known to produce H 2 S gas . Potential H 2 S evolution during preparation of ZOS 59‐99 was monitored by mass loss during reaction in conjunction with ELEM.…”

“…Inverse vulcanization (Scheme ) has emerged as an intriguing approach to valorizing agricultural waste through the combination of sulfur with plant‐derived olefins . The sulfur used in the inverse vulcanization process is itself a waste product from desulfurization of fossil fuels, so when sustainably sourced waste product olefins are employed the materials achieved can be comprised entirely of waste products.…”

Mercury Sorbents Made By Inverse Vulcanization of Sustainable Triglycerides: The Plant Oil Structure Influences the Rate of Mercury Removal from Water

“…It should be noted that these capacities are related to amount of active sites available for mercury binding on the surface of the polymer. By increasing the surface area of these polymer materials (by foaming or preparing the polymers on a high surface area support, for instance), an increase in capacity is likely possible—a strategy that has been validated for other polymers made by inverse vulcanization 23. Finally, from the Freundlich model, the sorption intensity parameter ( n ) can be used to assess if the metal uptake is favorable.…”

“…Thus, there remains a need for sustainable and low‐cost mercury sorbents that can be easily prepared and deployed in areas with limited economic resources. To address this need, polymeric sorbents for mercury made from elemental sulfur and renewable plant oils have emerged as attractive materials 16–23. The plant‐derived monomers are renewable and there is a surfeit of sulfur produced during petroleum refining, so these polymers can be prepared sustainably and on a large scale 24.…”