Sulphur and peroxide vulcanisation of rubber compounds – overview

Abstract

Vulcanisation is a process of transforming a plastic rubber compound into a highly elastic product by forming a three-dimensional cross-linked network structure in the rubber matrix. Many systems have been developed to vulcanise rubber compounds, among which sulphur and peroxide curing systems remain the most desirable. The application of sulphur systems leads to the forming of sulphidic cross-links between elastomer chains, while carbon–carbon bonds are formed in peroxide-curing. Both vulcanisation systems provide certain benefits to the cross-linked rubber articles, but also some disadvantages. The present work seeks to provide an overview on both vulcanisation systems; their composition, possibilities of their application, reaction mechanisms, structure of the cross-links formed and the main feature of the final cross-linked materials – vulcanisates.

Cross‐linking and properties of rubber magnetic composites cured with different curing systems

“…It is a complex process that leads to the forming of different types of sulfide cross‐links between macromolecules of rubber, namely, monosulfide C‐S‐C, disulfide C‐S 2 ‐C, and polysulfide cross‐links C‐S x ‐C (x = 3–6). In general, sulfur‐cured vulcanizates exhibit good tensile properties, high tensile and tear strength, and good elastic behavior, but weak high‐temperature stability and poor resistance to aging …”

“…C‐C bonds have higher dissociation energy in comparison with sulfidic cross‐links; therefore, peroxide‐vulcanized elastomers exhibit higher thermal stability and good resistance to thermo‐oxidative aging. Good electrical properties, low compression set, and no discoloration of the final products are next cognitive features of peroxide cured vulcanizates …”

“…However, in recent years, rubber materials have also found utilization in some specialty applications as in form of sensors, switches, biometic sensing devices, or shielding materials of magnetic and electromag- Ferrites are class of technologically important magnetic materials with high values of magnetocrystalline anisotropy and saturation magnetization, which allow wide application of these materials as permanent magnets. 1,2 Ferrite permanent magnets of general formula SrFe 12 O 19 or BaFe 12 O 19 contain approximately 80% of iron oxide and 20% of strontium or barium. Very good chemical stability, low specific weight, low price, suitable magnetic characteristics, and chemical and mechanical resistance are the main benefits of these materials.…”

“…In general, sulfur-cured vulcanizates exhibit good tensile properties, high tensile and tear strength, and good elastic behavior, but weak high-temperature stability and poor resistance to aging. [9][10][11][12][13] The application of peroxide curing system in cross-linking of elastomers leads to the forming of covalent carbon-carbon crosslinks between elastomer chain segments. C-C bonds have higher dissociation energy in comparison with sulfidic cross-links; therefore, peroxide-vulcanized elastomers exhibit higher thermal stability and good resistance to thermo-oxidative aging.…”

Agricultural proteins as multifunctional additives in ZnO‐free synthetic isoprene rubber vulcanizates

“…[1][2][3][4] Industrial cure recipes typically contain an activator system, accelerator, curing agent, reinforcing fillers, processing aid, retardant, compatibilizer, antidegradant, antioxidant, and rubber. It is a complex process in which a many-component system undergoes a series of reactions.…”