Inverse Vulcanization of Sulfur-Based Polymers

Inverse vulcanization is a direct copolymerisation of elemental sulfur—a major by-product of hydrodesulfurisation in the petrochemical industry—with unsaturated organic monomers. This approach stabilises the otherwise unstable linear polysulfur chains by crosslinking via C–S bonds, yielding high-sulfur polymers with typically more than 50 % sulfur content by mass. The resulting materials exhibit dynamic sulphur–sulphur bonds that confer unique properties such as self-healing, reparability and recyclability. Moreover, tailoring the choice of organic comonomer and reaction conditions enables control over mechanical strength, flexibility and degradability. The global significance of such polymers spans environmental remediation, energy storage, optics and advanced manufacturing, offering sustainable routes to transform inorganic waste sulfur into functional, high-performance materials.

Research from Nature Portfolio

Recent studies have expanded the chemical scope and practical feasibility of inverse vulcanization. One report introduced a catalytic approach that lowers reaction temperatures, broadens the range of compatible crosslinkers and minimises undesirable by-product formation, thereby enhancing yields and material properties. Another study employed a dual ring-opening strategy by copolymerising elemental sulfur with cyclic disulfides, harnessing the ring strain of five-membered 1,2-dithiolanes to drive polymerisation and produce degradable thermoplastics. These thermoplastics display tunable mechanical behaviour, dynamic self-repair capabilities and controlled degradability, representing a significant advance towards green, energy-efficient production of high-sulfur functional polymers.

Inverse Vulcanization of Sulfur-Based Polymers publication trend

The graph below shows the total number of articles in inverse vulcanization of sulfur-based polymers across all publications each year (not limited to Nature Index journals).

Technical terms

Inverse vulcanization: A copolymerisation method in which molten elemental sulfur reacts with unsaturated organic monomers to form crosslinked polysulfide polymers.

Comonomer: An unsaturated organic molecule that copolymerises with sulfur to create the polymer network.

Ring-opening polymerisation: A polymerisation mechanism in which cyclic monomers open their ring structure to form linear or crosslinked polymers.

Cyclic disulfide: A sulfidic ring compound (for example a 1,2-dithiolane) whose ring strain drives polymerisation with sulfur.

S–S metathesis: The dynamic exchange of sulphur–sulphur bonds within a polymer network, enabling self-healing and recyclability.

References

1. Water‐Soluble Ionic Liquid‐Containing Sulfur Polymers for Mercury Capture, Demulsification, and Antibacterial Activity. Advanced Functional Materials (2024).
2. Converting inorganic sulfur into degradable thermoplastics and adhesives by copolymerization with cyclic disulfides. Nature Communications (2024).
3. Ring‐Opening Terpolymerisation of Elemental Sulfur Waste with Propylene Oxide and Carbon Disulfide via Lithium Catalysis. Angewandte Chemie International Edition (2024).
4. Probe‐Based Mechanical Data Storage on Polymers Made by Inverse Vulcanization. Advanced Science (2024).
5. Catalytic inverse vulcanization. Nature Communications (2019).
6. Chemically induced repair, adhesion, and recycling of polymers made by inverse vulcanization. Chemical Science (2020).