Vulcanization of Rubber Compounds With Peroxide Curing Systems

Abstract

Vulcanization or curing is one of the most important processes in rubber technologies. During this process, plastic rubber compounds by parallel and subsequent physical and mainly chemical reactions change into highly elastic products—vulcanizates. The fundamental goal of curing is forming chemical cross-links between rubber macromolecules, which leads to the formation of a three-dimensional network or rubber matrix. A number of curing systems have been introduced in cross-linking of elastomers; each system has its own characteristics and composition; therefore, vulcanizates with different properties also can be prepared. We characterize organic peroxides as curing agents and their decomposition mechanisms and characteristics and bring a detailed view to understanding mechanisms between peroxides and different types of rubber matrices. Then, we focus on the classification and characterization of co-agents used in peroxide cross-linking and explain the mutual interactions and reaction mechanisms between peroxide, co-agents, and rubber matrices in relation to the properties of prepared materials. Finally, the drawbacks and the main features of final cross-linked materials are outlined.

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

“…These structures can be considered as the chemical or physical cross‐linking points of the composites. Additionally, the formation of ionic clusters through static electronic attractions with the contribution of zinc ions from coagent molecules was also observed . It becomes evident that ZDA as coagent in peroxide vulcanization reinforces the rubber matrix.…”

“…Peroxide radicals can potentially react with elastomers by abstraction of allylic hydrogens from the chains or by addition to the double bonds of unsaturated rubbers. Both hydrogen abstraction and addition mechanism may proceed simultaneously to form elastomer radicals (macroradicals) . The microstructural elements of elastomers are the main factors that determine which mechanism is dominant.…”

“…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 …”

“…Good electrical properties, low compression set, and no discoloration of the final products are next cognitive features of peroxide cured vulcanizates. 12,[14][15][16] Cross-linking of elastomers with peroxides can be effectively improved by using coagents. [17][18][19][20] Coagents are multifunctional lowmolecular-weight organic molecules that are highly reactive toward free radicals.…”

Molecular evolution during dynamic vulcanization of polyolefin mixtures for lead‐free thermoplastic vulcanized

“…Vulcanization of polyolefins is a well-known process and is widely used for producing rubber materials. 1,2 A similar process was used to produce thermoplastic vulcanisates (TPV) from mixtures of polyolefin elastomers and thermoplastics polymers 3 Since 1996, Mixer Spa has produced medium voltage (MV) insulation compounds based on EPDM and EPDM/LDPE blends which are now commercially available. 4,5 The complex materials with optimized thermoplastic elastomeric response were producer by MIXER in its laboratory by a structural design of composition followed by dynamic crosslinking.…”