To promote the vulcanization of butyl rubber, several types of substances are commonly added:
Sulfur: As butyl rubber has low unsaturation, sulfur is used as the vulcanizing agent. To accelerate the vulcanization process, fast-acting accelerators such as thiurams or sulfenamides are typically combined with sulfur.
Accelerators: In addition to high-speed accelerators, other types like dibutylthiourea (DBTU), CZ, or MTT-80 can be used. These accelerators hasten the vulcanization reaction and enhance the efficiency of the process.
Activators: A combination of zinc oxide and stearic acid often serves as the activation system. This duo aids in improving the vulcanization effect, ensuring uniform curing and boosting the physical properties of the vulcanizate.
Resin Vulcanization Systems: Alkylphenol formaldehyde resin or halogenated alkylphenol formaldehyde resins may be employed as vulcanizing agents. For specific applications, small amounts of halogen-containing compounds like chloroprene rubber or halobutyl rubber could be added to speed up the curing rate.
Quinone Dioxime Vulcanization System: Para-quinone dioxime is a frequently used vulcanizing agent that can be used alone or in conjunction with lead oxide, zinc oxide, sulfur, or thiazole-type accelerators. It is characterized by rapid vulcanization and results in vulcanizates with high tensile strength.
Special Vulcanizing Agents: Such as IBSH, tailored for butyl rubber vulcanization, are also available. The selection and ratio of these additives depend on the product specifications or manufacturer recommendations.
In summary, promoting the vulcanization of butyl rubber involves carefully choosing and combining sulfur, accelerators, activators, and possibly auxiliary vulcanizing agents to achieve the desired level of vulcanization and optimal rubber properties.
