Initiator
Category: Reagents & Chemicals
An Initiator is a substance designed to start a chemical reaction, particularly during polymerization. Its function is to produce reactive species, like free radicals, that then participate in the reaction with monomers, ultimately forming polymers. Precise control over the polymerization process relies on the careful selection and use of initiators, ensuring the desired polymer structure is created.
Common Types of Initiators in Polymerization
| Initiator | Type | Polymerization Method | Example Use |
|---|---|---|---|
| Benzoyl peroxide | Organic peroxide | Free radical polymerization | Used in making polystyrene and PVC |
| Azo compounds | Azo initiator | Free radical polymerization | AIBN (Azobisisobutyronitrile) for acrylates |
| Hydrogen peroxide | Inorganic peroxide | Free radical polymerization | Used in emulsion polymerization |
| UV light + photoinitiator | Photoinitiator | Photopolymerization | Used in 3D printing resins and coatings |
| Aluminum alkyls | Organometallic | Ziegler–Natta polymerization | Used for polyethylene and polypropylene |
| Lewis acids (e.g., BF₃) | Cationic initiator | Cationic polymerization | Used in polymerizing isobutylene |
| Stannous octoate | Tin-based compound | Ring-opening polymerization | Used in making polylactic acid (PLA) |