3,5,5-Trimethylhexanoyl peroxide

3,5,5-Trimethylhexanoyl peroxide (CAS 3851-87-4), also supplied commercially as Di-(3,5,5-trimethylhexanoyl) peroxide, is an organic peroxide used as a free-radical initiator and curing agent across polymer and rubber manufacturing.

Its controlled decomposition profile makes it suitable for low-to-moderate temperature polymerization processes where precise initiation is required. In plastics manufacturing, it initiates free-radical polymerization of vinyl monomers.

This includes PVC, polystyrene, and acrylics, enabling consistent molecular weight distribution in bulk and suspension processes. Rubber compounders use it as a cross-linking agent to achieve targeted vulcanization profiles.

It is particularly effective in EPDM and silicone elastomers. In coatings and UV-cure adjacent systems, it drives radical-initiated cure of resin formulations where thermal activation is preferred over photoinitiators.

Adhesive and sealant producers apply it to cure acrylic and peroxide-curable systems requiring defined pot life and throughput temperatures. This peroxide is commercially available as a liquid solution.

It is most commonly supplied at 75% active concentration in a diluent to reduce handling hazards and improve dosing accuracy. Technical grade is the standard market offering for industrial applications.

Due to its classification as an organic peroxide, it is typically supplied in temperature-controlled packaging. Buyers should confirm defined storage requirements with their supplier to ensure product stability.