Polyurethane synthesis and its associated materials generally employ two main categories of catalysts: tertiary amine catalysts and organometallic catalysts.
Amine Catalysts:
Amine catalysts are commonly applied in the manufacture of polyurethane foam plastics and can be further classified into the following subtypes:
1.Aliphatic amine catalysts
2.Cycloaliphatic amine catalysts
3.Alcohol compound catalysts
4.Aromatic amine catalysts
5.Organometallic Catalysts:
In formulations for polyurethane elastomers, adhesives, coatings, sealants, waterproof coatings, paving materials, and more, organometallic compounds, such as dibutyltin dilaurate (DY-12), find frequent use. They are highly effective in facilitating the reaction between isocyanate groups and hydroxyl groups. In formulations containing water, these compounds also accelerate the reaction between water and isocyanates. Specific catalysts, like organolead compounds, may be employed in formulations for specialized applications, such as rubber tracks.
Organometallic compounds are organic compounds that form direct bonds between metal atoms and carbon atoms, typically containing M-C bonds. These compounds encompass carboxylates and metal alkyl compounds, with metal elements mainly including tin, potassium, lead, mercury, zinc, among others, with organotin compounds being the most commonly used.