Peroxidvernetzung

Peroxidvernetzung, or peroxide crosslinking, is a chemical method used to form a three‑dimensional polymer network by introducing organic peroxide compounds that decompose to reactive radicals. When heated or exposed to light, the peroxide splits to generate radical species which can abstract hydrogen from polymer chains or add to double bonds, creating macroradicals. These macroradicals then recombine to create covalent bonds between different polymer chains, producing crosslinks or junction points that restrict chain mobility and yield an insoluble, thermally stable material.

This crosslinking approach is widely applied to natural and synthetic rubbers, such as natural rubber, styrene–butadiene rubber, and ethylene‑propylene‑diene monomer elastomers, as well as to certain thermoplastic elastomers and polyolefins. Peroxide curing is popular in rubber compounding and in the production of adhesives, coatings, and heat‑resistant elastomeric components. Compared with sulfur vulcanization, peroxide crosslinking can provide cleaner networks with better chemical and aging stability and often avoids odor associated with sulfur chemistry. However, it can also lead to residual peroxide or by‑products, potential discoloration, and a tendency toward brittleness at high crosslink densities if not properly controlled.

Process parameters include the selection of peroxide type (for example, dicumyl peroxide, tert‑butyl hydroperoxide, or benzoyl peroxide), as well as the dosage, temperature, and cure time to achieve the desired crosslink density. Safety considerations are important, since peroxides are reactive and can pose storage and handling risks.