Exploring hybrid vulcanization system in high‐molecular weight EPDM rubber composites: A statistical approach

Abstract

Elastomeric compound development is a multi-objective optimization task, and it contains vulcanization packages that crosslink the matrix. The deciding factors for vulcanization systems are the nature of elastomer, service temperature, processing methods and vulcanizate properties. Accelerated sulfur and organic peroxide are examples of vulcanization systems; each has its advantages and shortcomings. The peroxide-based system shows a high level of temperature stability while its flexibility is inferior to sulfur vulcanization. This study is finetuning a hybrid vulcanization system containing a combination of ultra-fast accelerated sulfur and a peroxide system; it also optimizes the vulcanization package ratios concerning various rheological and vulcanizate properties with the help of the Taguchi method. Ethylene propylene diene rubber (EPDM) is chosen as the basic matrix due to its excellent viability and commercial application with both the vulcanization systems. The formulations are optimized to combine the advantages of both the vulcanization systems. The results indicate that the vulcanization is sulfur-driven, but peroxide influences by selecting the crosslink sites and type. The hybrid system uses more components, but proper optimization helps to reduce the quantity of vulcanization packages with an improvement in physio-mechanical properties; it also helps to reduce the discharge of carcinogenic accelerator by-products, such as nitrosamine.

Combined Sulfur and Peroxide Vulcanization of Filled and Unfilled EPDM-Based Rubber Compounds

“…EPDM alkyl and allyl macroradicals can also add to the double bonds in diene monomer units. For steric reasons, the macromolecular radical thus formed would not propagate with another diene unit, but probably terminates via hydrogen transfer with the formation of allyl/alkene and alkyl/alkene cross-links [ 32 , 33 , 34 , 35 , 36 , 37 ].…”

“…The recombination of alkyl and allyl macroradicals leads to formation of allyl/allyl, alkyl/alkyl and alkyl/allyl cross-link combinations. EPDM and allyl macroradicals can also add to the double bonds in diene monomer units steric reasons, the macromolecular radical thus formed would not propagate with ano diene unit, but probably terminates via hydrogen transfer with the formation of ally kene and alkyl/alkene cross-links [32][33][34][35][36][37].…”

An investigation on mechanical, electrical, and rheological characteristics of ultra‐high molecular weight (UHMW)‐EPDM/PP blends‐based conductive thermoplastic vulcanizates (CTPVs)

“…Though at 20 phr filler loading the droplet size increases but due to the presence of reinforcing CCB filler the mechanical properties are higher for sample, C20. [ 45–48 ]…”

“…Though at 20 phr filler loading the droplet size increases but due to the presence of reinforcing CCB filler the mechanical properties are higher for sample, C20. [45][46][47][48] Finally, from the morphology study, it can be concluded that uniform droplet type morphology and smaller size can be achieved at the 10 phr level, which is optimized with the reference of the other mechanical and rheological properties. [49] 3.…”

Functional rubber composites based on silica-silane reinforcement for green tire application: the state of the art

“…10) [62]. Mixing is a key to all multi-component materials such as polymer bends [63,64], polymer composites [65,66], thermoplastic vulcanizates [67][68][69][70], and rubber composites [3,71]. Optimized silane concentration or silica content in rubber composite will not result in the desired performance properties if not mixed properly.…”