What is the action mechanism of rubber accelerator?

The action mechanism of rubber accelerator mainly includes the following aspects:

Activating crosslinker:

The crosslinking agent of rubber is achieved by vulcanization reaction. Rubber accelerator acts as activator in vulcanization reaction, which can accelerate the decomposition of crosslinking agent and form crosslinking structure.

Modified rubber molecules:

Rubber accelerators can modify rubber molecules and change their spatial structure and molecular chain length. This modification enables the formation of a closer cross-linked structure between rubber molecules, thereby improving the physical and chemical properties of rubber.

Inhibit side reactions during the vulcanization reaction:

Vulcanization reaction is a kind of chemical reaction, which is easy to produce some side reactions, such as bulk reaction, overcrosslinking, undercrosslinking and so on. Rubber accelerators can inhibit these side reactions and improve the efficiency and stability of rubber vulcanization reaction.

Specific to different types of accelerators, the mechanism of action may be different. For example, in the case of secondary sulfonamide accelerators, they are able to react with sulfur molecules to form active intermediates. This active intermediate has the characteristics of a non-crosslinked polysulfide with a vulcanization promoting group at the end. When they slowly decompose to produce free radicals, the active free radicals react with rubber hydrocarbons to obtain vulcanized rubber.

In the actual formulation of rubber products, a single accelerator is rarely used, but a variety of agents are used to control the vulcanization rate and scorch time. This principle can further improve the performance and stability of rubber products.

In general, rubber promoters play a vital role in the production process of rubber products, they significantly improve the performance and quality of rubber products by activating crosslinking agents, modifying rubber molecules and inhibiting side reactions.