peroxidevulkanisaatio

Peroxide vulcanization is a chemical process used to cure or cross-link polymers, typically elastomers, using organic peroxides. This method is distinct from traditional sulfur vulcanization and is often employed for polymers that are difficult to vulcanize with sulfur, such as silicone rubber, EPDM (ethylene propylene diene monomer), and fluoroelastomers.

The process involves heating the polymer in the presence of an organic peroxide. At elevated temperatures, the peroxide decomposes, generating free radicals. These free radicals abstract hydrogen atoms from the polymer chains, creating reactive sites. The free radicals on different polymer chains then combine, forming strong carbon-carbon cross-links between them. This cross-linking network transforms the soft, plastic polymer into a more elastic and durable material with improved mechanical properties, such as higher tensile strength, better heat resistance, and reduced compression set.

Compared to sulfur vulcanization, peroxide curing generally offers superior heat aging resistance and lower compression set, making it suitable for high-temperature applications. However, it can sometimes result in a less efficient cure rate and may produce a characteristic odor due to the decomposition byproducts of the peroxide. The choice of peroxide and curing conditions, such as temperature and time, are critical for achieving optimal cross-linking and desired material properties.